Background: An increased prevalence of cleft lip and/or palate (CL/P), a major congenital anomaly, has been observed in the offspring of women with elevated body mass index (BMI) before pregnancy. Likewise, gestational comorbidities, such as hypertension and diabetes mellitus, also increase the risk of CL/P; however, the risk linked to the coexistence of these conditions in women with higher BMI on birth prevalence of CL/P remains unclear. This study focused on the combined effects of a high BMI before pregnancy and gestational comorbidities on the birth prevalence of CL/P.

Methods: Among 98,373 live births from the Japan Environment and Children’s Study (JECS), a nationwide birth cohort, 255 mothers of infants with CL/P (74, 112, and 69 infants born with cleft lip, cleft lip and palate, and isolated cleft palate, respectively) were included in the analyses. The association of CL/P birth prevalence with pre-pregnancy BMI and gestational comorbidities (hypertension and diabetes) was examined using multivariate logistic regression analyses after multiple imputations, with adjustments for several maternal (age at delivery, smoking habits, and alcohol intake) and child-related (sex and prevalence of other congenital diseases) variables, obtained through medical record transcriptions and self-reports on JECS transcription forms.

Results: Higher prevalence rates of overweight, gestational hypertension, and gestational diabetes mellitus were found in mothers of infants with CL/P (16.1%, 6.3%, and 4.7%, respectively) than in the control group (10.4%, 3.1%, and 3.1%, respectively). The odds ratio [95% confidence interval] for childbirth with CL/P was increased in mothers with high BMI before pregnancy (1.58 [1.11–2.24]). Furthermore, gestational hypertension and diabetes coexisting with high BMI additionally increased the odds ratios for childbirth with CL/P (2.91 [1.28–6.61] and 2.12 [0.87–5.19], respectively).

Conclusion: High maternal BMI, particularly when accompanied by gestational hypertension, was significantly associated with an increased prevalence of childbirth with CL/P.

Background: Self-care is increasingly recognized as the foundation of person-centered healthcare and a key driver for simultaneously improving population health outcomes and reducing healthcare expenditures. While the Self-Care Inventory (SCI) has been validated in several languages, Japan lacks a standardized instrument for assessing self-care in the general adult population. Moreover, it remains unclear whether the SCI reflects culturally specific self-care behaviors and retains its psychological measurement properties in non-Western contexts. Addressing both aspects, this study aimed to evaluate the Japanese version of the SCI (JSCI) in terms of its psychometric properties and its association with concrete health behaviors.

Methods: We adapted the JSCI following COSMIN guidelines using forward/backward translation, expert review, and cognitive debriefing. Psychometric evaluation was based on two samples: a nationwide web-based survey (n = 504) and a community-based paper survey (n = 75). Structural validity was examined via CFA; internal consistency via Cronbach’s alpha and McDonald’s omega; and test–retest reliability via ICCs. Convergent and criterion validity were assessed through correlations with relevant psychological constructs. Measurement invariance and DIF across modes were tested, and associations with five external self-care behaviors were evaluated using AUC.

Results: The hypothesized three-factor structure of the JSCI was supported across both administration modes (CFI = 0.926–0.942; SRMR < 0.06), although some subscales had elevated RMSEA. Internal consistency was acceptable to high (α = 0.75–0.85; ω = 0.81–0.92). ICCs indicated moderate to good temporal stability. JSCI scores correlated with self-care efficacy and other related constructs, supporting convergent and criterion validity. Configural invariance was confirmed, and no significant DIF was detected across modes. JSCI scores modestly discriminated individuals engaging in concrete self-care behaviors such as physical activity, strength training, Helicobacter pylori testing, and having a regular primary or dental care provider (AUCs = 0.62–0.80).

Conclusions: The JSCI demonstrated satisfactory psychometric properties and structural validity across diverse research settings. Its observed associations with a range of meaningful self-care behaviors support the scale’s ecological and practical relevance in the Japanese context. The JSCI may serve as a reliable tool for evaluating and promoting self-care in both research and population health initiatives.

Background: The long-term impact of symptom classification on quality of life (QOL) and economic outcomes among individuals with long coronavirus disease (COVID) remains poorly understood. This study aimed to clarify the situation of long COVID in Japan by analyzing patients using cluster classification.

Methods: This multicenter, retrospective cohort study enrolled 515 patients with COVID-19 and followed up for 36 months via standardized questionnaires. Patients were classified based on: 1) symptom trajectory over time and 2) symptom cluster profiles at 3 months.

Results: While the number of symptoms decreased, fatigue and dyspnea frequently persisted, whereas anosmia and dysgeusia declined. Cough and sputum decreased gradually. The proportion of patients with 5–9 symptoms increased. The mean (interquartile range) presenteeism scores were lower in the continuous (60 [50–80]) and relapse groups (65 [48–80]) than in the recovered group (70 [50–80]). The multiple symptoms cluster had the worst SF-36, presenteeism, and absenteeism scores (47.2 [44.7–49.8], 48.8 [27.5–72.5], and 10.9 [0.0–11.0], respectively).

Conclusions: Patients with continuous and multiple symptoms experienced persistently lower QOL and greater economic burden up to 36 months after COVID-19 diagnosis. The long-term effects of long COVID are not only physical but also mental and economical. Thus, further research is needed to clarify the economical and physiological impact of long COVID.

Background: Epstein-Barr (EB) virus infection stimulates the production of vascular endothelial growth factor (VEGF), which contributes to the progression of angiogenesis. Angiogenesis plays an important role in the development of atherosclerosis. Since serum anti-early antigen EB virus IgG (EBV EA-IgG) titer is a sign of active EB virus infection, EBV EA-IgG titer could be associated with atherosclerosis. The number of minor (T) alleles in VEGF polymorphism rs3025039 has been reported to be inversely associated with serum VEGF concentration, suggesting that rs3025039 might have a strong influence on the association between EBV EA-IgG titer and atherosclerosis. By focusing on the role of VEGF in the development of atherosclerosis, this study aimed to investigate the association between active EB virus infection and atherosclerosis.

Methods: A cross-sectional study of 2,661 older Japanese individuals aged 60–89 years who participated in annual health check-ups during 2017–2019 was conducted. Logistic regression was used to evaluate the association between EBV EA-IgG titer and atherosclerosis in relation to rs3025039 genotype. The influence of rs3025039 (T) allele carrier status on the association between EBV EA-IgG titer and atherosclerosis was also evaluated by using logistic regression.

Results: Among rs3025039 CC-homozygotes, with the lowest EBV EA-IgG titer tertile as the reference, the multivariable odds ratio (95% confidence interval) was 1.11 (0.82, 1.50) for the medium tertile and 1.07 (0.78, 1.47) for the high tertile. Among rs3025039 (T) allele carriers, the corresponding values were 1.44 (0.88, 2.36) and 1.88 (1.15, 3.05), respectively. There was a significant interaction between rs3025039 (T) allele carrier status and the association between EBV EA-IgG titer and atherosclerosis (adjusted p = 0.0497).

Conclusion: EBV EA-IgG titer was significantly positively associated with atherosclerosis only among participants who are genetically less likely to have progressive angiogenesis. An angiogenesis-related genetic factor was revealed as a determinant of the association between EBV EA-IgG titer and atherosclerosis. These findings introduce a novel concept that could explain the association between viral infection and atherosclerosis.

Background: Long screen time hours may be associated with behavioral problems in children. To better understand the relationship between children’s behavioral problems and screen time, it the associated risk factors must be subdivided based on the purpose underlying screen use. This study examined the relationship between screen time based on intended usage and behavioral problems in Japan.

Methods: This study included 3,332 children aged between 7–17 years from the Hokkaido Study on Environment and Children’s Health. From October 2020 to October 2021, the children and their parents answered questionnaires on the children’s screen use duration (never used, <30 min, ≥30 min & <1 hour, ≥1 h & <2 h, ≥2 h) based on seven intended usage categories: watching television/video, video gaming, reading books/comics, sending/receiving e-mail/messages, browsing/posting on social networking services, studying for classes/homework, drawing/editing pictures/photos/videos, along with the Strengths and Difficulties Questionnaire (SDQ). Logistic regression was used to analyze the association between screen time, purpose of children’s screen use, and behavioral problems across the 13 SDQ total scores.

Results: The mean ± standard deviation age of the participants was 12.4 ± 2.4-years-old, 487 (14.6%) children were determined to have behavioral problems, and the duration of screen time increased with their age. The children’s primary purposes for screen use were watching television/video, video gaming, sending/receiving e-mail/messages, and browsing/posting on social networking services. Children who reported playing video games for ≥2 hours on weekdays had higher odds of problematic total difficulties scores than never user (Odds Ratio: 2.10, 95% confidence interval: 1.45–3.06).

Conclusion: Long video gaming screen time is associated with behavioral issues, hyperactivity/inattention, and prosocial behaviors in children. Conversely, watching television and videos for 30 min–1 h per day, using e-mail or messaging, and using social networking services were significantly association with reduced odds ratio for peer relationship problems as compared to children who never engaged in these activities. Longitudinal follow-up is needed to further examine screen time and problem behaviors.

Background: Although many studies have reported the therapeutic effects of hot spring bathing on various diseases, its influence on healthy individuals is not well understood. Myoban Onsen, a sulfur-rich hot spring in Beppu City, Japan, is traditionally believed to improve skin conditions, relieve fatigue, and promote relaxation. However, scientific verification of these effects, particularly their impact on gut microbiota and related metabolic outcomes in healthy individuals, remains scarce. This study aimed to evaluate the effects of Myoban hot spring bathing on gut microbiota composition and SCFA concentrations in healthy individuals.

Methods: In this study, 16 healthy adult males (n = 16) participated in Myoban hot spring bathing four times over two weeks. Fecal samples were collected before and after the intervention, and 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS) were performed to analyze gut microbiota composition and organic acid concentrations. The effects of hot spring bathing were evaluated using the Wilcoxon matched-pair signed-rank test to compare pre- and post-intervention.

Results: After Myoban hot spring bathing, there was a significant increase in beneficial gut bacteria, Bifidobacterium, Blautia, and Anaerostipes, compared to pre-bathing (p = 0.0012, p = 0.0103, and p = 0.0017, respectively). Conversely, significant decreases were observed in Parabacteroides, Alistipes, and Oscillibacter (p = 0.0125, p = 0.0215, and p = 0.0125, respectively). Significant increases in SCFAs, including acetic acid, propionic acid, and butyric acid, were observed after Myoban hot spring bathing (p = 0.0067, p = 0.0125, and p = 0.0302, respectively). These findings suggest that Myoban hot spring bathing may benefit healthy adult males.

Conclusions: This study suggests that Myoban hot spring bathing may improve gut health in healthy males. The observed increases in beneficial bacteria and SCFAs indicate a potential contribution to improved health status through modulation of the gut environment.

Trial registration: Registration number: UMIN000055229, retrospectively registered.

Background: Chronic constipation is a long-term problem that decreases children’s quality of life. Information and communication technology devices have developed rapidly in recent decades and have had various impacts on children. This prospective cohort study examined the association between television/digital versatile disc (TV/DVD) screen exposure time at age 1 and the risk of chronic constipation at age 3.

Methods: Data from 63,697 infants in the Japan Environment and Children’s Study (JECS) were analyzed. We divided participants into five groups according to TV/DVD exposure time per day: no exposure (0 h), short exposure (<1 h), middle exposure (1.0–<2.0 h), long exposure (2.0–<4.0 h), and very long exposure (≥4 h). Logistic regression analysis was performed to assess the association between TV/DVD exposure time and the risk of constipation. For logistic regression analysis, odds ratios (ORs) were adjusted for sex, parents’ education, household income, nursery school, feeding contents, and obesity. The interaction between the sexes was also examined.

Results: The prevalence of constipation for males, females, and all participants at age 3 was 9.3, 11.0, and 10.1%, respectively. The TV/DVD screen time distribution per day at age 1 was 10.6% for none, 34.1% for short, 29.9% for middle, 19.2% for long, and 6.2% for the very long exposure group. After adjusting for confounding factors, a dose-response pattern was identified between TV/DVD exposure time and constipation in all participants (p for trend < 0.001). The adjusted ORs increased progressively in the short (OR 1.15, 95% confidence interval [CI] 1.04–1.27), middle (OR 1.22, 95% CI 1.11–1.35), long (OR 1.37, 95% CI 1.24–1.52), and very long exposure groups (OR 1.53, 95% CI 1.35–1.74). This association was not significantly different between the sexes (p for interaction = 0.36).

Conclusions: Longer TV/DVD exposure time at age 1 was associated with the risk of chronic constipation at age 3. Excessive screen exposure may need to be avoided from infancy to decrease the risk of chronic constipation in later years.

Background: Japan lacks comprehensive reports on the nationwide voluntary vaccine coverage. The effectiveness of public subsidies in promoting vaccination has not been fully investigated. Therefore, we aimed to estimate the nationwide coverage of voluntary vaccines, compare it with that of national immunization program (NIP)-included vaccines, and investigate the effectiveness of public subsidies.

Methods: We obtained nationwide monthly vaccine market data for rotavirus, Haemophilus influenzae type b (Hib), diphtheria, tetanus toxoid, acellular pertussis, inactivated poliovirus (DTaP-IPV), and mumps vaccines; estimated recipient numbers; and calculated coverage as the proportion of children from October 2011 to March 2022. Regarding the NIP-included vaccine, we compared vaccine coverage calculated from nationwide annual market data with that estimated by World Health Organization (WHO)/United Nations Children’s Fund (UNICEF), using Bland-Altman analysis.

Results: The estimates of Hib and DTaP-IPV vaccine coverage derived from market data were slightly higher than the WHO/UNICEF estimates, with mean differences of 0.05 (95% CI: 0.02–0.07) for Hib and 0.03 (95% CI: 0.01–0.05) for DTaP-IPV. The coverage of the rotavirus vaccine gradually increased long before the implementation of national subsidies, reaching 0.9 in 2020. Hib vaccine coverage had already achieved 1.0 by January 2012. The coverage of the DTaP-IPV vaccine was approximately 0.6–0.8 in 2013, reaching 1.0 in 2014. The coverage of mumps vaccine increased gradually from 2011 to 2021.

Conclusions: Despite the possibility of overestimation, our estimates may serve as a valuable surrogate for actual vaccine coverage in Japan. An increasing trend in rotavirus and mumps vaccine coverage was observed when these vaccines were categorized as voluntary. Although vaccination policies differ from country to country, it would be beneficial to share findings on the impact of subsidies in Japan with other countries.

Background: This cross-sectional study examined meal patterns based on daily energy intake distribution and their associations with nutrient and food intake, diet quality, and body mass index (BMI).

Methods: Body height, weight, habitual dietary intake and the Healthy Eating Index (HEI)-2020 score by eating occasion were assessed using the validated Meal-based Diet History Questionnaire among employees (465 males and 193 females aged 20–75 years) in the Tokyo Metropolitan Area. Meal patterns were extracted based on % energy intake from breakfast, lunch, dinner, and snacks using K-means clustering by sex. Dietary intake, HEI-2020 score, and BMI were then compared between sex-specific meal patterns.

Results: The identified patterns were “large lunch and dinner” (n = 299), “three meals-balanced” (n = 97), and “large dinner” (n = 69) patterns in males and “large dinner” (n = 79); “large afternoon snack” (n = 54) and “large lunch” (n = 60) patterns in females. The HEI-2020 scores were the highest for dinner, followed by breakfast, lunch, and snacks in any meal pattern. Males with the “large dinner” pattern had lower intakes of rice, bread, carbohydrates, dietary fibre, and thiamine; higher intake of alcoholic beverages; and higher HEI-2020 scores than those with other patterns. Females with a “large dinner” pattern had a lower intake of bread, confectionery, total and saturated fats, and carbohydrates; higher intake of fish, meat, and alcoholic beverages; higher HEI-2020 scores; and lower BMI. Thus, a meal pattern with higher energy intake distribution at dinner was associated with higher diet quality among males and females and lower BMI among females in Japanese workers.

Conclusions: These findings suggest that improving the quality of the meal with the highest energy contribution could help enhance overall dietary quality and metabolism.

Background: Heated tobacco products (HTPs) are widely used in Japan, following cigarettes, but their health effects remain unclear. HTPs are often considered a less harmful alternative to cigarettes and are commonly used by adults with asthma, even though smoking is one of the most obvious and treatable factors in asthma. We aimed to elucidate the association between HTP use and asthma symptoms in adults with asthma.

Methods: A total of 3,787 individuals with asthma were extracted from the data in the Japan COVID-19 and Society Internet Survey 2023, an ongoing longitudinal internet-based cohort study conducted by a nationwide internet research company in Japan. They were categorized into three groups (never, past, and current smokers) based on cigarette use. The association between HTP use and worsening of asthma symptoms within the previous 2 months in each group was analyzed using univariate and multivariate logistic regression analyses. Both exposure and outcomes were assessed by self-reporting.

Results: Among the participants, 2,470 (65.2%) were never smokers, 845 (22.3%) were past smokers, and 472 (12.5%) were current smokers. Overall, the proportion of HTP users was 429 (11.3%), and worsened asthma symptoms were observed in 400 (10.6%) individuals. The total proportion of HTP users and worsened asthma symptoms was 70 (2.8%) and 259 (10.5%) among never smokers, 180 (21.3%) and 72 (8.5%) among past smokers, and 179 (37.9%) and 69 (14.6%) among current smokers. After adjusting for confounders, the odds ratio (OR) was 3.25 (95% confidence interval [CI] 1.86–5.68, p < 0.001), 1.47 (95% CI 0.93–2.34, p = 0.1), and 2.23 (95% CI 1.46–3.43, p < 0.001) for never, past, and current cigarette smokers with HTP use, respectively, where never smokers without HTP use were set as the standard.

Conclusion: The use of HTPs, not only cigarette smoking, was associated with worsening of asthma symptoms in adults with asthma. Therefore, people need to understand the harmful effects of HTPs on asthma symptoms.

Background: Children’s respiratory health demonstrates particular sensitivity to air pollution. Existing evidence investigating the association between short-term ozone (O₃) exposure and childhood pneumonia remains insufficient and inconsistent, especially in low- and middle-income countries (LMICs).

Method: To provide more reliable and persuasive evidence, we implemented a multi-city, time-stratified case-crossover design with a large sample size, using data from seven representative children’s hospitals across major geographical regions in China. To avoid the impact of the COVID-19 pandemic, individual-level medical records of inpatient children under 6 years of age diagnosed with pneumonia during 2016–2019 were collected. Conditional logistic regression models were fitted for each city, and city-specific estimates were pooled through a meta-analysis using a random-effects model.

Results: In total, the study included 137,470 pediatric pneumonia hospital admissions. The highest pooled estimate for O₃ occurred at lag0–1, with a 10 µg/m³ increase in O₃ associated with a 1.57% (95% CI: 0.67%–2.48%) higher risk of pediatric pneumonia hospital admissions. Stratified analyses indicated that the effects of O₃ were robust across different sexes, age groups, and admission seasons. We also observed a statistically significant increase in risk associated with O₃ concentrations exceeding the World Health Organization Air Quality Guidelines (WHO-AQGs).

Conclusions: This study revealed a significant positive association between O₃ and pediatric pneumonia hospital admissions. Our findings substantially strengthen the evidence base for the adverse health impacts of O₃, underscoring the importance of O₃ pollution control and management in reducing the public health burden of pediatric pneumonia.

Background: Supporting the mental health of researchers is essential to maintaining human resources and advancing science. This study investigated the association between Japanese medical researchers’ perceptions of research evaluation processes and their psychological well-being.

Methods: We performed a web-based self-administered questionnaire survey. The questionnaires were distributed to each academic society through the Japanese Association of Medical Sciences from December 2022 to January 2023. These questionnaires targeted medical researchers. Exposure was the medical researchers’ perceptions of quantitative indicators for evaluating medical research and researchers. The outcome was psychological well-being, measured using the Japanese version of the World Health Organization-Five Well-Being Index (WHO-5). Multivariable-adjusted logistic regressions were conducted to investigate the association between individual attitudes toward research evaluation and psychological well-being. Stratified analyses by research fields, i.e., clinical, basic, and social medicine, were also performed.

Results: A total of 3,139 valid responses were collected. After excluding 176 responses from research fields of other than clinical, basic, or social medicine, 2,963 researchers (2,185 male, 737 female, and 41 other) were analyzed. Prevalence of poor well-being (WHO-5 score <13) was 28.3% in the researchers. The highest number of medical researchers was in clinical medicine (n = 500) followed by basic medicine (n = 217) and social medicine (n = 121). Medical researchers who considered research funding slightly important/not important for researcher evaluation had poorer psychological well-being than those who considered it especially important (slightly important: adjusted odds ratio (aOR) 1.33, 95% confidence interval (CI) 1.03–1.71; not important: aOR 1.53, 95%CI 1.10–2.12). This tendency was stronger among basic medical researchers than clinical or social medical researchers. The research field significantly modified the relationship between research funding received and interaction with poor psychological well-being both additively (P = 0.030) and multiplicatively (P = 0.024).

Conclusions: The discrepancy between medical researchers’ attitudes toward research evaluation and the current state of research evaluation in their research community may worsen their psychological well-being. The influence of this discrepancy differs among clinical, basic, and social medicine. Appropriate evaluation of medical research and researchers in each field can facilitate improving their psychological well-being via the resolution of this discrepancy.

Per- and polyfluoroalkyl substances (PFAS) have recently been shown to affect human health at low levels in the blood, according to epidemiological evidence. Consequently, human exposure to these chemicals should be strictly controlled to prevent health risks. This review reports on the potential sources of PFAS using Japan as an example. Tap water has attracted attention as a source of exposure to PFAS. PFAS have also been detected in the air, in household dust, and in consumer products. Furthermore, in the general population, diet is the most common source of exposure, and there is particular concern about human exposure to PFAS accumulated in seafood. Continuous monitoring is important for appropriate management of exposure for both humans and the environment.

Background: Previous studies have shown that old age and cold temperatures are risk factors for bathing-related accidents (BRAs) in Japan. The differences between outdoor and indoor temperatures are believed to depend on the housing type (detached houses or apartment buildings). This study aimed to investigate the associations between age, temperature, and BRAs according to housing type in Japan.

Methods: We included cases in which patients were transported by ambulance from domestic bathrooms between April 2016 and March 2022 in Nagoya city. Age-specific BRA incidence rates measured by 5-year age groups, temperature-specific age-adjusted standardized incidence rates (SIRs) for BRA calculated by temperature quintile groups, and the BRA risk regarding temperature based on a time-stratified case-crossover (CCO) design were compared between detached houses and apartment buildings.

Results: We observed 4,848 ambulance dispatches owing to BRAs (3,083 in detached houses and 1,765 in apartment buildings; SIR for detached houses compared to apartment buildings: 1.37; 95% confidence interval [CI]: 1.33–1.43). The ratio of detached houses to apartment buildings in the age-specific BRA incidence was almost the same in middle-aged people, but it significantly increased from the age of 70 years onward (incidence rate ratio for the 70–74-years age group: 1.74; 95% CI: 1.43–2.11). Temperature-specific SIR for detached houses compared to apartment buildings was not significantly different in the hottest temperature quintile but increased significantly in the other colder temperature quintiles (SIR in coldest quintile: 1.56; 95% CI: 1.47–1.66). BRA risk based on CCO design increased significantly with a decrease in temperature in detached houses (risk ratio [RR] for 3 °C: 1.25; 95% CI: 1.05–1.47), but not in apartment buildings (RR for 3 °C: 1.07; 95% CI: 0.86–1.34).

Conclusions: Detached houses had higher BRA incidence rates than apartments. Older age and lower temperatures, which are risk factors for BRAs, were more prevalent in detached houses than in apartment buildings. Thus, public health measures that focus on detached houses are necessary for preventing BRAs in Japan.

Background: Meals are provided at nursery schools for Japanese preschool children, and this may result in different energy and nutrient intakes on weekdays and weekends. The purpose of this study was to obtain basic information for public nutrition policies in early childhood by examining differences in energy and nutrient intakes of preschool children between weekdays and weekends using meal categories such as breakfast, lunch, dinner, and snacks.

Methods: Energy and nutrient intakes were examined in 761 Japanese preschool children (423 boys, 338 girls) aged 3–6 years attending childcare facilities in seven regions in Japan. Data collection was based on non-consecutive four-day dietary records (two weekdays, two weekend days) in 2019 or 2020. Energy and nutrient intake by meal category were compared using a generalized linear mixed model adjusted for demographic factors.

Results: Total energy intake was significantly higher on weekdays for boys (1,478 vs. 1,415 kcal) and girls (1,349 vs. 1,296 kcal) (both P < 0.001). Weekday lunches had higher protein content and essential micronutrients such as potassium, iron, vitamins, and lower fat, saturated fatty acids, and salt, compared to weekend lunches. Similarly, weekday snacks also had significantly higher nutritional consumption for most nutrients compared to weekend equivalents.

Conclusion: These findings suggest that meals at nursery schools, particularly lunch and snacks, result in more desirable nutrient intake in preschool children. On weekdays, children consume meals with higher nutrient density, possibly due to the role of dietitians in menu planning. However, some children still fail to meet the Dietary Reference Intakes for Japanese, indicating a need for improvements in nursery school and home meals. More communication is needed between nursery schools and families, including sharing menus and recipes is essential. The results of this study are of value for development of public health nutrition strategies targeting early childhood.

Background: Changes in socioeconomic inequalities in health behaviours following the COVID-19 pandemic remain unknown, particularly among Japanese school-aged adolescents. Therefore, in this study, we examined changes in socioeconomic inequalities in school-aged adolescents’ health behaviours, including physical activity (PA), screen time (ST), sleep duration, breakfast consumption, and bowel movement frequency, before and after the pandemic.

Methods: This three-wave repeated cross-sectional study utilised data from the 2019, 2021, and 2023 National Sports-Life Survey of Children and Young People in Japan, analysing data from 766, 725, and 604 participants aged 12–18 years, respectively. Favourable health behaviours were defined as moderate-to-vigorous PA of ≥60 min/day, ST <2 h/day, sleep duration of 8–10 h, daily breakfast consumption, and bowel movements at least every 3 days. Absolute and relative socioeconomic inequalities were quantified using the slope index of inequality (SII) and the relative index of inequality (RII). Temporal changes were analysed using quadratic trend analyses, employing interaction terms between socioeconomic status and survey year.

Results: Significant quadratic trends indicated that socioeconomic inequalities in breakfast consumption decreased substantially from 2019 (SII: 20.7%, RII: 5.09) to 2021 (SII: −0.1%, RII: 0.95) but resurged in 2023 (SII: 16.2%, RII: 3.70). This resurgence may have been primarily driven by changes among those in the moderately low-income (poverty level II) and higher-income groups, which had a breakfast consumption rate of 81.0, 87.0, and 76.4% in 2019, 2021, and 2023, and 88.7, 82.1, and 87.5%, respectively. Among low-income households, adherence to PA recommendations significantly declined from 18.6% to 5.3%, and ST adherence worsened over the study period. No significant inequalities or trends were observed for sleep duration or bowel movement frequency across survey years.

Conclusions: Socioeconomic disparities in breakfast consumption among Japanese school-aged adolescents resurfaced after initially narrowing during the pandemic, likely driven by changes in moderately low-income and higher-income groups. Among low-income households, adherence to PA and ST guidelines declined over time. However, at the population level, socioeconomic inequalities in PA did not exhibit a consistent trend of widening or narrowing. This study highlights the need for sustained public health initiatives to address these socioeconomic disparities.

Background: Organic chemicals have been known to cause allergic diseases such as bronchial asthma and hypersensitivity pneumonitis; however, the possibility that they do not cause irreversible pulmonary fibrosis has not been considered. Polyacrylic acid (PAA), an organic chemical, has caused irreversible progressive pulmonary fibrosis in exposed workers, indicating its potential to induce pulmonary inflammation and fibrosis. Although intratracheal instillation studies are commonly used for evaluating lung pathology, traditional methods face challenges with chemical substances, particularly nanoparticles, which tend to aggregate in suspension and prevent uniform pulmonary distribution. Such aggregation alters the qualitative and quantitative responses to lung injury, limiting accurate assessment of lung pathology. To overcome this limitation, we developed a ‘molecular dispersion method’ that uses pH modification to negative charges to PAA particles, maintaining their dispersion. Using this method, we investigated the effects of PAA on pulmonary inflammation and fibrosis in a rat model.

Methods: F344 rats were intratracheally instilled with PAA using molecular dispersion (0.1 mg/rat, 1.0 mg/rat), PAA without molecular dispersion (1.0 mg/rat), and normal saline (control group). Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months after exposure to examine inflammatory and fibrotic responses.

Results: PAA caused persistent increases in neutrophil influx in the bronchoalveolar lavage fluid (BALF) from 3 days to 1 month following instillation. In histopathological findings, the group with molecular dispersion had almost no inflammatory masses in the lung tissue compared to the group without molecular dispersion, and exhibited relatively uniform dispersion.

Conclusion: Intratracheal instillation of dispersed PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA might have pulmonary inflammogenicity and fibrogenicity. Intrapulmonary dispersion of PAA particles following intratracheal instillation studies using the molecular dispersion method was similar to that following inhalation studies.

Background: Pneumonia is a major global public health concern. Taking antioxidant nutrients has attracted attention for their potential role in reducing pneumonia mortality. Although studies in Western countries have evaluated this association, the current evidence remains controversial, and research in Asia remains limited. This cohort study investigated the association between dietary antioxidant nutrients intake and pneumonia mortality in Japanese population.

Methods: Data were collected from the Japan Public Health Center-based Prospective Study between 1995 and 1998, with follow-up until the end of 2018. The intake of antioxidant nutrients was assessed using a validated food-frequency questionnaire. The Cox proportional hazard model was employed to calculate hazard ratios (HRs) and p-trends for pneumonia mortality, adjusting for potential confounding factors including age, area, body mass index, smoking status, alcohol intake, physical activity, postmenopausal status, occupation, coffee intake, green tea intake, antihypertensive medication use, vitamin-supplement use, and total energy intake.

Results: The analysis included data from 39,850 men and 46,705 women. Over a median follow-up of 20.8 years, 813 men and 477 women died from pneumonia. The multivariable model revealed that a higher intake of cryptoxanthin (p-trend = 0.027 in men; 0.019 in women), lycopene (p-trend = 0.016 in women), vitamin C (p-trend = 0.022 in men), and vitamin E (p-trend = 0.031 in women) was significantly associated with a reduction in pneumonia mortality.

Conclusions: Higher dietary intake of cryptonxanthin, lycopene, and vitamins C and E was associated with a low risk of pneumonia mortality in Japanese adults.

Background: Hyperthermia (HT), while a cancer treatment approach, isn’t always effective alone. Therefore, identifying hyperthermia enhancers is crucial. We demonstrated that Mito-TEMPO ([2-[(1-Hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) amino]-2-oxoethyl]-triphenylphosphanium, MT) acts as a potent thermosensitizer, promoting cell death in human cervical cancer (HeLa) cells.

Methods: Cells were pretreated with 0.4 mM MT for 5 minutes, followed by exposure to hyperthermia (42 °C for 60 minutes). The impacts of MT/HT on cell viability, proliferation, apoptosis, endoplasmic reticulum (ER) stress, apoptosis-related proteins and autophagy, autophagy-related proteins expression were measured. The relationships between autophagy and apoptosis were further investigated using the specific autophagy inhibitor chloroquine (CQ) and the autophagy inducer rapamycin (Rapa).

Results: The combined treatment reduced the mitochondrial membrane potential (MMP) and increased ROS production. It also upregulated the pro-apoptotic protein Bax and downregulated anti-apoptotic proteins such as Bcl-2 and MCL-1. As a result, Caspase-3 was activated. Additionally, the combined treatment upregulated the expression of p-PERK/PERK, ATF-4, CHOP proteins. Moreover, the combined treatment also increased the expression of LC3 II and p62, decreased expression of LAMP 1 and Cathepsin D and increased lysosomal pH, indicating coordinated changes in autophagy regulation. Notably, intensification of apoptosis induced by the combined treatment was observed with CQ, whereas attenuation was seen with Rapa.

Conclusions: MT effectively enhanced HT-induced apoptosis in HeLa cells. Elevated ER stress and interruption of autophagy flux are the possible underlying molecular mechanisms for this phenomenon. These findings suggested MT can act as a potential thermosensitizer, highlighting its versatility in cancer treatment strategies.

Background: Although smoking rates have been declining worldwide, new types of tobacco products have been gradually spreading in recent years, especially in Japan, where heated tobacco products (HTPs) users are rapidly increasing. Oxidative stress caused by reactive oxygen species (ROS) is one of the causes of smoking-induced carcinogenesis, respiratory diseases, and cardiovascular diseases. However, information on the amount of ROS contained in mainstream smoke from HTPs is limited. In this study, we measured the amount of ROS generated from HTPs to evaluate the oxidative stress-related toxicity of HTPs.

Methods: IQOS ILUMA, glo hyper+, and Ploom X ADVANCED were used as the HTP devices. Mainstream smoke was collected from each HTP according to Health Canada Intense regime (smoke volume, 55 mL; smoke duration, 2 s). The collected ROS were reacted with 2,7′-dichlorodihydrofluorescein reagents, and the amount of ROS was calculated as H₂O₂ equivalent from the fluorescence intensity obtained.

Results: The ROS in the mainstream smoke from IQOS ILUMA, glo hyper+ (high-temperature mode), and Ploom X ADVANCED was found to be 48.8 ± 8.6, 86.6 ± 12.6, and 40.8 ± 5.7 nmol H₂O₂/stick, respectively (n = 6, mean ± standard deviation), with the highest being from glo hyper+ (high-temperature mode). The amount of ROS was significantly higher in the high-temperature mode of glo hyper+ than in the standard mode of glo hyper+. Additionally, the estimated amount of ROS from smoking 20 heated sticks per day (674–2160 nmol H₂O₂/day) was equivalent to 2.2–96 times the amount of daily exposure to ROS in the urban atmosphere (approximately 22–300 nmol H₂O₂/day).

Conclusions: We found that ROS is generated from HTPs of different devices. This study suggests that HTPs users may be exposed to much more ROS than they are exposed to in normal life.

Background: Exposure to air pollution and adherence to a healthy lifestyle have been identified to be related to sarcopenia. However, the interactive effects between these two factors remain insufficiently elucidated. The present study was designed to investigate the potential interaction exposure to air pollution with healthy lifestyle on the risk of developing sarcopenia.

Methods: In the retrospective cohort study, all data was extracted from China Health and Retirement Longitudinal Study. Household air pollution was assessed based on the utilization of solid fuels for cooking and heating. A lifestyle score was constructed comprising information on physical activity, smoking, drinking and sleeping time. Multivariate logistic regression model was used to assess the effects of household air pollution and healthy lifestyle score on sarcopenia, separately. We further explored the additive interaction between household air pollution and healthy lifestyle score to sarcopenia using the interaction table developed by T Anderson. Relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (SI) were used to evaluate the additive interactive effect.

Results: 2,114 participants were included in this study. The result indicated that exposed to household air pollution [adjusted relative risk (RR) = 1.80, 95% confidence interval (CI): 1.15–2.94] and unhealthy lifestyle (adjusted RR = 1.46, 95%CI: 1.04–2.03) were both significantly associated with increased risk of sarcopenia. Furthermore, participants exposed to both household air pollution and an unhealthy lifestyle exhibited a significantly higher risk of sarcopenia relative to those without household air pollution exposure and maintaining a healthy lifestyle (adjusted RR = 2.44). But RERI, AP, and SI suggested that there is no statistically significant additive interaction between household air pollution exposure and healthy lifestyle factors in relation to sarcopenia risk.

Conclusion: Household air pollution in conjunction with an unhealthy lifestyle confers a significantly higher risk of sarcopenia compared to either factor in isolation, with no evidence of a significant additive interaction between these two risk factors.

Background: Despite some studies identifying a potential association between obesity and chronic obstructive pulmonary disease (COPD) risk, previous research had overlooked the dynamic nature of body weight over time, leading to inconsistent findings. The purpose of this study is to elucidate the relationship between adult weight change and COPD risk by adjusting for potential confounding factors.

Methods: We conducted a retrospective analysis using data from ten NHANES cycles (1999–2018), including adults aged 40–74 years. Weight change patterns were assessed using BMI at three time points and classified into five categories per period. Absolute weight change was also grouped into five levels. Multivariate logistic regression models, incorporating sampling weights, were used to examine associations between weight change and COPD, adjusting for demographic and lifestyle covariates.

Results: Compared with participants who maintained normal weight, stable obesity participants had increased risk of COPD from age 25 years to 10 years before the survey (OR = 1.45, 95% CI = 1.15 to 1.83), in the 10 years period before the survey (OR = 1.75, 95% CI = 1.47 to 2.08), and from age 25 years to survey (OR = 1.84, 95% CI = 1.46 to 2.31). Three periods indicate that weight gain in adulthood was associated with risk of COPD. In addition, substantial weight gain of more than 20 kg was associated with a higher risk of COPD. In stratified analyses, we also observed a more significant association between weight change and the risk of COPD in never smokers compared to former smokers.

Conclusions: Our study suggested that stable obesity and weight gain in adulthood were associated with an increased risk of COPD compared to those who maintain a normal weight, and that the association between weight gain and the incidence of COPD appears closer in patients who have never smoked.

The recent three leading risk factors for global disease burden in the world are, in descending order, high blood pressure, tobacco smoking including second-hand smoke, and alcohol use. Alcohol use increases the risk for many acute and chronic health consequences including cancer, road injury and suicide as well as alcohol use disorder. It is known that there is a U- or J-shaped relationship between alcohol consumption and all-cause mortality. The descending leg of the curve showing this relationship is best explained by a decrease in the risk of cardiovascular disease, especially ischemic heart disease, among light-to-moderate alcohol drinkers. However, this relationship carries risks of confounding and selection bias, including the so-called healthy drinker bias. Furthermore, biogenic compounds other than ethanol present in wine may be partially responsible for the beneficial effect, although this also includes several confounding factors such as the drinking patterns associated with wine preference. While some studies suggest that light-to-moderate alcohol consumption may offer cardiovascular benefits, these findings are likely influenced by confounding factors and do not negate the substantial public health burden associated with alcohol use. In fact, from a population health perspective, reducing harmful alcohol consumption remains a critical priority. Social policies aimed at lowering alcohol intake and limiting drinking opportunities can contribute to longer life expectancy by preventing alcohol-related diseases. Unhealthy alcohol use is one of the four major behavioral risk factors—along with smoking, physical inactivity, and poor diet—that accounted for approximately 50% of all deaths and about six years of life expectancy lost between 2001 and 2008. Targeted interventions are particularly important for men and individuals with lower educational attainment, as alcohol-related mortality is higher in men and contributes more to socioeconomic disparities in life expectancy among men than among women. Alcohol consumption is influenced by socioeconomic factors such as education, income, and occupation. While higher socioeconomic status is associated with more frequent drinking, lower status is associated with higher consumption volume. Given that alcohol-related deaths and life expectancy trends vary across countries and over time, public health strategies should be tailored to specific social and temporal contexts.

Background: Neck cooling is a practical method for preventing heat-related illness, however, its effectiveness in general workers is not well established. This study aimed to assess the effects of neck cooling on core body temperature and other physiological markers during exercise in a hot environment.

Methods: This randomized crossover trial was conducted from November 2023 to April 2024 at the Shared-Use Research Center at UOEH. Fourteen healthy adult males participated in the study under two conditions: with neck cooling (COOL) and without neck cooling (CON). All participants completed both conditions, and the order of condition assignment was determined by a random draw. Participants first rested for 10 minutes in a 28.0 °C, 50% relative humidity environment, followed by a rest in a 35.0 °C, 50% relative humidity environment for another 10 minutes. In the COOL condition, participants wore a neck cooler containing 1,200 g of ice while exercising at 50% Heart Rate Reserve on a bicycle ergometer for 20 minutes. Afterward, they rested for 15 minutes in the hot environment while still wearing the cooler.

Main outcome measures: Core body temperature (rectal and esophageal), forehead skin temperature, and heart rate were continuously monitored and compared using a mixed model. Estimated sweat volume was calculated based on changes in body weight before and after the experiment.

Results: At the end of the rest period, no significant differences were observed between the COOL and CON conditions in rectal temperature (37.76 ± 0.18 °C versus 37.75 ± 0.24 °C, p = 0.9493), esophageal temperature (37.75 ± 0.30 °C versus 37.76 ± 0.23 °C, p = 0.7325), forehead skin temperature (36.87 ± 0.29 °C versus 36.88 ± 0.27 °C, p = 0.2160), or heart rate (104.18 ± 7.56 bpm versus 107.52 ± 7.40 bpm, p = 0.1035). Estimated sweat loss was similar between conditions (578 ± 175 g for CON versus 572 ± 242 g for COOL, p = 0.5066). While more participants felt cooler in the COOL condition, RPE showed no significant difference.

Conclusion: Neck cooling did not significantly affect core temperature or perceived exertion. Maintaining close contact with the skin at sufficiently low temperatures or utilizing cooling methods that prevent excessive negative feedback may be necessary to enhance the effectiveness of neck cooling.

Background: High visceral fat mass (FM) is associated with a high risk of cardiometabolic morbidity. Meanwhile, loss of skeletal muscle (lean mass, LM) has been suggested to contribute to metabolic diseases.

Methods: We investigated associations between cardiometabolic diseases and dual energy X-ray absorptiometry (DXA)-measured body composition indices, including the FM index (FM/height²), percent body fat, trunk-to-appendicular fat ratio (TAR), trunk-to-leg fat ratio (TLR), LM index (LM/height²) and FM-to-LM ratio in 595 community-dwelling elderly Japanese men (mean age, 74 years; standard deviation, 6; range, 65 to 94). Hypertension was identified as high blood pressure and/or the use of antihypertensive drugs. Diabetes was identified as high hemoglobin A1c and/or the use of antidiabetic drugs. The ability of DXA-based indices to discriminate between the presence and absence of cardiometabolic diseases was evaluated using area under the curve (AUC) calculated by receiver operating characteristic curve analysis.

Results: Body mass index, FM index, percent body fat, TAR, TLR and FM-to-LM ratio were significantly associated with hypertension (P < 0.05). TAR and TLR, but not body mass index, FM index, percent body fat, LM index and FM-to-LM ratio, showed significant positive associations with diabetes. The AUC for the LM index was significantly lower than those for the FM index, percent body fat and FM-to-LM ratio. No associations were observed between the LM index and hypertension, dyslipidemia and diabetes.

Conclusion: The association between cardiometabolic function and LM, which includes skeletal muscle, may not be as pronounced or stronger than associations between cardiometabolic function and FM. Further detailed studies are needed to clarify how skeletal muscle contributes to cardiometabolic disease.

Background: Although serum carotene may contribute to dementia prevention, there is a lack of longitudinal evidence for early cognitive decline before dementia symptoms. The aim of this study was to examine whether serum carotene levels were associated with annually evaluated cognitive trajectories among the Japanese general population.

Methods: Among 581 baseline participants, 199 individuals (83 males; mean age [min, max], 62.7 [39, 90] years) who underwent cognitive assessments more than twice after baseline were analyzed. “Attention” levels were assessed using one- and three-target Digit Cancellation Tests (D-CAT1 and D-CAT3). “General cognitive ability” was assessed by the short version of Mini-Mental State Examination (SMMSE). Serum carotenes (α-carotene, β-carotene and lycopene) were measured by high-performance liquid chromatography. After the measurements, we calculated total carotene levels by summing up the levels of all measured carotene. Carotene levels were categorized into three groups for analysis (low: 0%–25%, middle: 25%–75%, and high: 75%–100%). A linear mixed model was used to estimate the slope of the D-CAT score trajectory and to compare it between three categories.

Results: Compared with the middle carotene group, decline of attention was faster in the D-CAT1 for low β-carotene (β = −3.48, p = 0.035), lycopene (β = −3.10, p = 0.062), and total carotene (β = −4.75, p = 0.003), but not for α-carotene (β = −2.60, p = 0.111). For the D-CAT3, decline of attention was faster in the group of low lycopene (β = −3.17, p = 0.002) and total carotene (β = −2.17, p = 0.037) compared with the middle carotene group, while no clear association for α-carotene (β = −0.67, p = 0.521) and β-carotene (β = −0.64, p = 0.639). There were no clear associations between serum carotene and the SMMSE score.

Conclusions: These findings suggest low levels of serum lycopene are associated with a decline of attention in the setting of the general population.

Background: Only prospective cohort studies can capture changes in work conditions and their effects on health. Such studies are rare in bus drivers, despite their high rates of injuries and diseases. The three existing cohorts have limited exposure data, collected at baseline and thus uninformative on exposure and exposure-effect dynamics. Therefore, we aimed to develop the Swiss Transport Personnel Health Cohort (TRAPHEAC) and to anticipate and prevent potential bias.

Methods: To set up the study protocol, we first organized the stakeholder consultation and available data inventory. Second, we mapped the exposure-outcomes pairs to list the most prevalent occupational hazards, and conducted exposure measurement campaigns. Third, we built the Swiss Bus-Exposure Matrix for physical-chemical hazards and Bus-Ergonomics Matrix for visual and biomechanical constrains. These matrices contain 705 bus models operated in Switzerland since 1980 and enable assessing current and past exposure when merged with bus drivers’ work histories.

Results: We opted for an original study design combining prospective cohort part starting at 2024 and a retrospective part with nested case-control studies. Bus drivers will be invited through three complementary channels: unions, companies, and social media. The eligibility screening, information, and consent form signature and registration will be conducted using the study web-site modules. Registered bus drivers will first receive a comprehensive inclusion questionnaire, then a yearly follow-up questionnaire to assess and update the drivers’ work histories. Validated self-reported questionnaires will be used for assessing additional health outcomes (e.g., stress, sleep problems, musculoskeletal disorders, burnout) and individual, occupational and live-style related factors (e.g., personality, ICT use, physical activity). Hospital records (with diagnosed diseases, diagnosis dates and treatments) centralized since 2000 by the Swiss Federal Statics Office will be used for assessing disease prevalence, incidence and case-control status. Advanced statistical analysis will be conducted to address etiological and methodological questions (e.g., individual and joint causal effects of multiple exposures and exposure components; time-varying exposure and outcome variables and confounders mixtures).

Conclusions: The yearly assessment of both exposure and health outcomes should enable capturing changes in work conditions and their effects on bus drivers’ health and well-being over time and facilitate the tailoring, implementation and evaluation of preventive interventions.

Background: The effect of air pollution on annual change rates in grip strength and body composition in the elderly is unknown.

Objectives: This study evaluated the effects of long-term exposure to ambient air pollution on change rates of grip strength and body composition in the elderly.

Methods: In the period 2016–2020, grip strength and body composition were assessed and measured 1–2 times per year in 395 elderly participants living in the Taipei basin. Exposure to ambient fine particulate matters (PM_2.5), nitric dioxide (NO₂), and ozone (O₃) from 2015 to 2019 was estimated using a hybrid Kriging/Land-use regression model. In addition, long-term exposure to carbon monoxide (CO) was estimated using an ordinary Kriging approach. Associations between air pollution exposures and annual changes in health outcomes were analyzed using linear mixed-effects models.

Results: An inter-quartile range (4.1 µg/m³) increase in long-term exposure to PM_2.5 was associated with a faster decline rate in grip strength (−0.16 kg per year) and skeletal muscle mass (−0.14 kg per year), but an increase in body fat mass (0.21 kg per year). The effect of PM_2.5 remained robust after adjustment for NO₂, O₃ and CO exposure. In subgroup analysis, the PM_2.5-related decline rate in grip strength was greater in participants with older age (>70 years) or higher protein intake, whereas in skeletal muscle mass, the decline rate was more pronounced in participants having a lower frequency of moderate or strenuous exercise. The PM_2.5-related increase rate in body fat mass was higher in participants having a lower frequency of strenuous exercise or soybean intake.

Conclusions: Among the elderly, long-term exposure to ambient PM_2.5 is associated with a faster decline in grip strength and skeletal muscle mass, and an increase in body fat mass. Susceptibility to PM_2.5 may be influenced by age, physical activity, and dietary protein intake; however, these modifying effects vary across different health outcomes, and further research is needed to clarify their mechanisms and consistency.

Background: Older adults in Japan have the highest drowning mortality rate globally due to frequent bathing practices. Low outdoor temperatures have been linked to bath-related deaths; however, previous studies employed limited statistical models and focused on a single prefecture. Given Japan’s aging population, preventing bath-related deaths is a public health priority. This study aimed to analyze the association between outdoor temperature and bath-related drowning deaths across Japan from 1995 to 2020 (n = 110,938), examining regional variations and identifying contributing prefectural characteristics.

Methods: Daily counts of bath-related drowning deaths per prefecture were matched with daily mean temperature data from the Japan Meteorological Agency. Prefecture-level demographic and environmental data were obtained from Japan’s Official Statistics. We applied a generalized additive mixed model to examine the association between daily mean temperature and bath-related drowning death risk. Meta-regression was used to identify prefecture-level modifiers.

Results: Bath-related drowning death risk peaked at a daily mean temperature of 1.8 °C (relative risk [RR] 9.7, 95% confidence interval [CI]: 9.5–9.9), compared with the lowest risk at 30.3 °C. The association was stronger at mid-range temperatures, particularly among males and individuals aged ≥65 years. Among prefectures, Kagoshima—the southernmost prefecture on Japan’s main islands—had the highest maximum RR at 19.6 (95% CI: 16.2–23.6), while Hokkaido—the northernmost prefecture—had the lowest at 3.8 (95% CI: 3.4–4.3). Prefecture-level factors that strengthened this relationship included a lower prevalence of double-pane windows as a proxy of housing insulation and higher annual mean temperatures with ratio of RR change per one standard deviation increase of 0.76 (95% CI: 0.69–0.83) and 1.27 (95% CI: 1.18–1.37), respectively.

Conclusions: Warmer prefectures in southern regions exhibited greater maximum-to-minimum risk ratios compared to cooler northern prefectures. This paradoxical finding underscores the importance of region-specific interventions to reduce bath-related deaths.

Background: Neglected tropical diseases (NTDs) and malaria pose a major health challenge, especially in low- and middle-income countries.

Methods: Initially, we performed a descriptive analysis of the Global Burden of Disease (GBD) 2021 database, categorizing data by subtypes. Next, linear regression models were employed to analyze temporal trends. We then utilized four predictive models to forecast the future burden. Additionally, we explored the relationship between estimated annual percentage change (EAPCs) and age-standardized rates (ASRs), as well as Human Development Index (HDI) scores for 2021. Furthermore, decomposition analysis was applied to assess the influence of aging, population dynamics, and epidemiological changes. Lastly, frontier analysis was conducted to examine the connection between disease burden and sociodemographic development.

Results: In 2021, NTDs and malaria contributed significantly to the global disease burden, with considerable disparities across genders, age groups, Socio-demographic Index (SDI) regions, GBD regions, and individual countries. From 1990 to 2021, both the number of cases and the associated ASRs have shown a recent downward trend. The EAPCs are positively correlated with ASRs and HDI scores. Projections indicate a continued decline in disease burden through 2046. Additionally, our decomposition analysis highlighted the positive impact of aging and epidemiological shifts on the reduction of the disease burden. Finally, frontier analysis revealed that countries and regions with higher SDI scores have greater potential for further reducing their health burden.

Conclusion: While the global burden of NTDs and malaria has improved overall, significant disparities remain across regions and countries. Our findings highlight the importance of implementing targeted intervention strategies and maintaining sustained investments to tackle the ongoing challenges.

Background: High temperatures are known to be associated with an increased risk of self-harm, but the influence of demographic changes and country-level indicators on the burden of heat-related self-harm remains unclear. This study examined the key factors driving changes in self-harm mortality linked to high temperatures and explored their impact at the country level.

Methods: This is an ecological study that analyzes data from the 2021 Global Burden of Disease (GBD) study, the World Bank, and the Climate Research Unit (CRU) were analyzed. Decomposition analyses were used to identify key factors driving changes in high temperature-related self-harm mortality between 1990 and 2021. A panel data model assessed the impact of national indicators on heat-related self-harm mortality.

Results: In 2021, 14,885 deaths globally were attributed to heat-related self-harm, a 41.94% increase from 1990, with low-middle SDI regions accounting for 47.84% of these deaths. While the global death rate from heat-related self-harm declined slightly over this period, South Asia and low-middle SDI regions contributed most to the decline. However, population aging exacerbated mortality rates. Demographic and meteorological factors were also linked to heat-related self-harm.

Conclusion: The global decline in heat-related self-harm mortality is largely driven by reductions in females, low-middle SDI regions, and South Asia. However, population aging and growth in these regions have added to the mortality burden, slowing the overall decline. Factors such as population density are also associated with heat-related self-harm. Targeted measures are needed to mitigate heat-induced self-harm more effectively in future.

Background: Our previous observational cohort study, the Kashima Scan Study (KSS), identified associations between lifestyle, cerebral small vessel disease (SVD) as detected by magnetic resonance imaging of the brain, and disease outcomes including cognitive impairment and vascular diseases. However, established modifiers of the outcomes such as genetic background, drinking and exercise habits, and socioeconomic status were not considered. Regarding genetic factors in particular, the ALDH2 rs671 variant, East Asian-specific diversity, and APOE status are expected to have strong effects. The aim of KSS-2 is to examine the interactions of genetic background, lifestyle factors including drinking habit, socioeconomic status, and/or SVD markers for cognitive impairment, vascular disease, and death.

Method: The KSS-2 is a prospective regional observational study of a healthy Japanese cohort that will clarify lifestyle habits to better maintain brain health from midlife by genotype. Japanese adults who underwent brain health checkups at their own expense are enrolled and will be followed-up for 10 years. We will extend the protocol of the KSS to include genetic background and potential confounding factors, including lifestyle (including drinking and exercise habit) and socioeconomic status, and perform survival analyses. The study outcomes are cognitive impairment, vascular events, and death.

Results: We enrolled 908 healthy adults (mean age 64.2 years; range 35 to 84 years; 41% male) from September 1, 2018 until December 31, 2024.

Conclusion: This study will provide important insights into the development of individualized health intervention strategies.

Background: The efficacy of routine childhood immunization depends on timely vaccine uptake and facility use patterns. This study examined the association between pediatric vaccination facility use patterns and routine childhood immunization uptake among children up to age eight years.

Methods: As part of the Kochi Adjunct Study of the Japan Environment and Children’s Study (JECS), we analyzed data from 1,644 participants whose Maternal and Child Health Handbook photographs were collected in the eighth year of the cohort study. Maternal and Child Health Handbook records determined immunization completion. Participants were categorized into four groups based on pediatric vaccination facility use patterns: single facility use throughout, multiple facility use during the first period, multiple facility use during the second period, and multiple facility use throughout both periods. Maternal and child characteristics were collected via paper-based questionnaires. Associations between facility use patterns, sociodemographic factors, and immunization completion were analyzed using chi-square tests and logistic regression.

Results: Overall, routine childhood immunization completion was observed in 1,259 (76.6%) participants. Chi-square tests indicated that marital status, educational level, lower parity, never smoking, not attending nursery, and breastfeeding practice for infants aged four months old were significantly associated with routine childhood immunization completion. Single facility use throughout the immunization period was observed in 1,011 (61.5%) participants. Multiple facility use (38.5%) was associated with higher odds of routine childhood immunization incompletion than single facility use. This association was the strongest for those who used multiple facilities throughout the vaccination period (adjusted odds ratio, 1.90; 95% confidence interval, 1.24–2.91).

Conclusions: Single pediatric facility use was associated with higher routine immunization uptake. Our findings suggest that encouraging the use of one medical institution for a child’s vaccinations may be a useful approach to consider when addressing vaccination coverage challenges.

Background: The objective of this study was to investigate the potential link between myopia in adolescents and exposure to per- and polyfluoroalkyl substances (PFASs).

Methods: This investigation included 1971 subjects with accessible PFAS level data, myopia status, and associated variables from four cycles of the National Health and Nutritional Examination Survey (NHANES). The investigation focused on specific PFAS compounds found in the serum, including perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS), chosen for their frequent detection. Owing to the skewed nature of the PFAS level data, the PFAS levels were log-transformed (Ln-PFAS) prior to analysis. Logistic regression, restricted cubic spline modeling, subgroup analysis, and sensitivity analysis were used to examine the associations between exposure to PFASs and the onset of myopia.

Results: PFOA levels were significantly associated with myopia risk (OR: 1.33; 95% CI: 1.05–1.69; P = 0.019). More specifically, with respect to the first quartile, the second quartile (OR_Q2: 1.69; 95% CI: 1.16–2.46; P = 0.007), third quartile (OR_Q3: 1.45; 95% CI: 1.03–2.03; P = 0.035), and highest quartile (OR_Q4: 1.58; 95% CI: 1.12–2.21; P = 0.010) of participants presented with increased myopia risk. Mediation analysis revealed that PFOA and myopia risk were partially mediated by serum albumin (ALB), with a mediation percentage of 22.48% (P = 0.008). A nonlinear inverted U-shaped relationship was identified between the level of PFOA and myopia risk (P for nonlinearity = 0.005).

Conclusion: Our findings suggest a potential link between exposure to PFOA and the likelihood of myopia development in young individuals and a mediating effect of serum ALB on this relationship. Notably, PFOA was identified as a key PFAS significantly contributing to the observed link between PFAS exposure and myopia risk. The potential threat of PFOA to myopia should be examined further.

Background: Depression among older adults is an important public health issue, and air and noise pollution have been found to contribute to exacerbation of depressive symptoms. This study examined the association of exposure to air and noise pollutants with clinically-newly-diagnosed depressive disorder. The mediating role of individual pro-inflammatory markers was explored.

Methods: We linked National Health Insurance claim data with 2998 healthy community-dwellers aged 55 and above who participated in the Healthy Aging Longitudinal Study between 2009 and 2013. Newly diagnosed depressive disorder was identified using diagnostic codes from the medical claim data. Pollutants were estimated using nationwide land use regression, including PM_2.5 and PM₁₀, carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, and road traffic noise. Cox proportional hazard models were employed to examine the association between pollutants and newly developed depressive disorders. The mediating effect of serum pro-inflammatory biomarkers on the relationship was examined.

Results: Among the 2998 participants, 209 had newly diagnosed depressive disorders. In adjusted Cox proportional hazard models, one interquartile range increase in PM_2.5 (8.53 µg/m³) was associated with a 17.5% increased hazard of developing depressive disorders. Other air pollutants and road traffic noise were not linearly associated with depressive disorder incidence. Levels of serum tumor necrosis factor receptor 1 mediated the relationship between PM_2.5 and survival time to newly onset depressive disorder.

Conclusion: PM_2.5 is related to an increased risk of newly developed depressive disorder among middle-aged and older adults, and the association is partially mediated by the pro-inflammatory marker TNF-R1.

Background: Since the accident at Fukushima Daiichi Nuclear Power Plant (FDNPP), concerns have arisen in Japan regarding the presence of radionuclides in food. Moreover, exposure levels to ⁹⁰Sr and Pu isotopes in adults and those to ¹³⁴Cs+¹³⁷Cs, ⁹⁰Sr, and Pu (where Cs, Sr, and Pu are cesium, strontium, and plutonium, respectively) in children have not been examined. Therefore, this study employed a duplicate portion approach to examine dietary exposure levels of radionuclides in adults and children following the FDNPP accident.

Methods: The study spanned fiscal years 2012–2014 and was conducted in 10 prefectures: Hokkaido, Iwate, Miyagi, Fukushima, Ibaraki, Saitama, Tokyo, Kanagawa, Osaka, and Kochi. The participants provided portions of their meals for two non-consecutive days and completed questionnaires on the meal items. The activity concentrations of ¹³⁴Cs, ¹³⁷Cs, ⁹⁰Sr, and ^239+240Pu, which are targets of standard limits for radionuclides in foods in Japan, were determined according to the Radioactivity Measurement Series. The daily intake was calculated based on the radionuclide activity concentrations in the duplicate portion samples, and the committed effective doses were estimated using dose coefficients for the ingestion of each radionuclide provided by the International Commission on Radiological Protection.

Results: Approximately 80 duplicate samples were obtained in each fiscal year, and 242 samples were collected. The highest summed activity concentration of ¹³⁴Cs and ¹³⁷Cs was 11 Bq/kg, which was recorded in Date City (child) in 2013; this level was approximately one-ninth of the standard limit for general foods (100 Bq/kg). The committed effective dose from annual ingestion of the sample described above was 74 µSv, approximately 14 times lower than the maximum permissible level of 1 mSv/y. Pu was not detected and the ⁹⁰Sr activity concentrations were similar to those before the FDNPP accident.

Conclusions: For the samples examined in the present study, the ¹³⁴Cs, ¹³⁷Cs, ⁹⁰Sr, and ^239+240Pu dietary exposure levels were considerably lower than the regulatory levels and may not pose a health risk.

Background: The demand for aged-care services in Japan has surged due to the country’s aging population. Furthermore, nationwide survey on the current state of aged-care services revealed that the primary reason for the resignation of women working in these sectors was poor interpersonal relationships. Moreover, given that women working in aged-care services work in shifts around the clock to manage the health and safety of the people in their care, they are at high risk of health-related issues including insomnia symptoms. Thus, we aim to examine the association between levels of satisfaction with interpersonal relationships (LSIR) and insomnia symptoms for women working in aged-care services in Japan, as well as the effect of work–life imbalance on the association between LSIR and insomnia symptoms.

Methods: In this cross-sectional study, the participants were 472 women aged 18–60 years who worked in aged-care services in Japan in 2014–2016. Insomnia symptoms were measured using the Athens Insomnia Scale, and scores of 6 or greater indicated the presence of insomnia. LSIR were assessed through self-administered questionnaires and evaluated at three levels. The association between LSIR and insomnia symptoms was evaluated using a multinominal logistic regression model. Path analysis was used to examine the potential effects of LSIR on insomnia symptoms by incorporating covariates such as work–family conflict, marital status, and depressive symptoms.

Results: Compared to high LSIR, the multivariable-adjusted odds ratios (95% confidence interval) of insomnia symptoms were respectively 1.36 (0.81–2.30) and 2.42 (1.11–5.23) for medium and low LSIR. The path analysis showed that low LSIR were significantly associated with having high work-to-family (W-to-F) conflict and being single.

Conclusions: Low LSIR were significantly associated with insomnia symptoms among women working in aged-care services in Japan. High W-to-F conflict exacerbated this relationship. Therefore, enhancing interpersonal relationships may be necessary for preventing insomnia. However, due to the cross-sectional nature of our study, causality cannot be inferred. Further longitudinal research is needed to better understand these associations.

Background: Cardiovascular disease (CVD) is the predominant cause of mortality in China. However, the mechanisms linking sarcopenia to CVD remain poorly understood, particularly in normal-weight populations. Individuals with the absence of overweight or obesity may tend to experience missed opportunities for timely intervention. This study aimed to investigate the longitudinal association between sarcopenia and incidence of new-onset CVD in a normal-weight population, and to examine the mediating effect of functional limitation in this relationship.

Methods: We conducted a closed-cohort analysis using a nationwide sample of 4,147 middle-aged and older adults with normal weight in China. We performed Cox proportional hazards regression analysis to explore the associations of baseline sarcopenia with incident CVD. The difference method was applied to estimate the mediation proportion of functional limitation in this association.

Results: Over a mean follow-up period of 7.62 years, CVD occurred in 835 participants. In the multivariable-adjusted Cox model, individuals with sarcopenia exhibited a significantly higher likelihood of developing incident CVD compared to those without sarcopenia (adjusted hazard ratio [aHR] = 1.45, 95% confidence interval [CI]: 1.21–1.73, P < 0.001). Similar associations were observed for the incidence of heart disease and stroke. Functional limitation accounted for approximately 15.0% of the total effect of sarcopenia on incident CVD (P < 0.001).

Conclusions: Sarcopenia exerts both direct and indirect effects on incident CVD among middle-aged and older adults who are normal weight, with functional limitation serving as a significant mediator. Interventions targeting both sarcopenia and functional limitation may offer a promising strategy for enhancing cardiovascular health in this population.

Background: Research has demonstrated that heavy metals and cholesterol are associated with stress urinary incontinence (SUI) in women and that heavy metal exposure can cause dyslipidemia in humans. However, the potential mediating role of cholesterol in the relationship between heavy metals and female SUI remains unexplored.

Methods: The study utilized data from the National Health and Nutrition Examination Survey database from 2013–2018. Blood lead (Pb), cadmium (Cd), total mercury (Hg), manganese (Mn), selenium (Se), and methyl mercury (MeHg) were included in the study. The single and combined effects of the six metals exposure on SUI were examined using logistic analysis, restricted cubic spline (RCS) curves, weighted quantile sum (WQS) regression, and bayesian kernel machine regression (BKMR). The mediating effects of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were investigated through mediation analysis.

Results: The study included 2241 females, with 42.66% experiencing SUI. Initial analysis of six heavy metals revealed the associations between MeHg, Pb, Cd, total Hg, and SUI (all P < 0.05). WQS regression identified that Cd, Se, and Pb were major contributors to the mixed effect causing SUI. BKMR results indicated a positive mixed effect between six heavy metals and SUI. TC partially mediated the relationship of Pb, MeHg, and total Hg with SUI, and LDL-C partially mediated the association of Pb with SUI (all P for mediation < 0.05).

Conclusions: Blood heavy metal concentrations influence the development of female SUI, with blood cholesterol mediating the association between different heavy metals and SUI.

Background and aim: The association between physical activity (PA) and sarcopenia has mostly been investigated in older people, with few studies focused on earlier life stages. The present study aimed to determine whether higher PA levels are associated with a lower sarcopenia risk in middle-aged and early older people.

Methods: This was an 8-year follow-up study. Participants were 6,500 community-dwelling adults aged 40–74 years who participated in the baseline questionnaire survey conducted in 2011–2014 in Japan. Levels of total and leisure-time PAs at baseline were assessed using validated metabolic equivalent scores. Multi-frequency bioelectrical impedance analysis and handgrip strength measurement were performed in 2021–2022, and participants with low height-adjusted appendicular lean mass (<20th percentile) and low grip strength were diagnosed as having sarcopenia (outcome). Covariates were demographics, body size, lifestyle, and disease history at baseline.

Results: The prevalence of sarcopenia was 137/2926 (4.7%) for men and 127/3574 (3.6%) for women. Higher total PA levels were associated with lower odds of sarcopenia (P for trend = 0.0278), with the second highest group having a significantly lower OR (0.51) than the lowest group (reference) in women, but not in men. Regarding leisure-time PA, those engaged in leisure-time vigorous PA had a lower OR of sarcopenia than those who did not (OR = 0.67, P = 0.0625).

Conclusion: Higher levels of total PA are associated with a lower risk of sarcopenia in women but not in men, suggesting a sex difference in this association. In addition, high levels of vigorous leisure-time PA may be effective for preventing sarcopenia.

Background: Cancer is a major public health concern, particularly among middle-aged and elderly populations, who are disproportionately affected by rising cancer incidence. Environmental pollution has been identified as a significant risk factor for cancer development. China’s Carbon Emission Trading Policy (CETP), implemented in pilot regions since 2013, aims to reduce carbon emissions and improve air quality. This study evaluates the impact of CETP on pan-cancer incidence, with a focus on its effects on specific cancer types and vulnerable populations.

Methods: This quasi-natural experiment utilized data from the China Health and Retirement Longitudinal Study (CHARLS) and environmental data from the China National Environmental Monitoring Center (2011–2018). A staggered difference-in-differences (DID) model was employed to estimate the impact of CETP on cancer incidence. Robustness tests, including parallel trend tests, placebo analysis, and entropy balancing, validated the findings. Subgroup analyses were performed to assess the policy’s heterogeneous effects based on gender, Body Mass Index (BMI), and smoking status.

Results: CETP implementation significantly reduced the incidence of six cancer types: endometrial, cervical, gastric, esophageal, breast, and lung cancers. Overall, pan-cancer incidence significantly declined post-policy implementation (CETP × POST: −47.200, 95% CI: [−61.103, −33.296], p < 0.001). The policy demonstrated stronger effects in highly polluted areas and among individuals with poorer mental health. Subgroup analysis revealed that females, individuals with lower BMI, and non-smokers experienced more substantial benefits.

Conclusions: CETP significantly reduces cancer incidence by improving environmental quality and influencing mental health, with particularly strong effects observed among high-risk populations. This study highlights the important role of environmental economic policies in mitigating cancer burden and promoting public health. Future research should further explore the long-term impacts of this policy and its applicability across different national and regional contexts.

Background: Mitochondria, which harbor their own genome (mtDNA), have attracted attention due to the potential of mtDNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Although mtDNA-CN has been proposed as a simple and accessible biomarker for metabolic disorders such as metabolic dysfunction-associated steatotic liver disease, the underlying mechanisms and the causal relationship remain insufficiently elucidated. In this investigation, we combined longitudinal epidemiological data, animal studies, and in vitro assays to elucidate the potential causal relationship between reduced mtDNA-CN and the development of steatotic liver disease (SLD).

Methods: We conducted a longitudinal study using data from a health examination cohort initiated in 1981 in Yakumo, Hokkaido, Japan. Data from examinations performed in 2015 and 2022 were analyzed, focusing on 76 subjects without SLD at baseline (2015) to assess the association between baseline mtDNA-CN and subsequent risk of SLD development. In addition, 28-day-old SD rats were fed ad libitum on a 45% high-fat diet and dissected at 2 and 8 weeks of age. Blood and liver mtDNA-CN were measured and compared at each feeding period. Additionally, in vitro experiments were performed using HepG2 cells treated with mitochondrial function inhibitors to induce mtDNA-CN depletion and to examine its impact on intracellular lipid accumulation.

Results: Epidemiological analysis showed that the subjects with low mtDNA-CN had a significantly higher odds ratio for developing SLD compared to high (odds ratio [95% confidence interval]: 4.93 [1.08–22.50]). Analysis of the animal model showed that 8 weeks of high-fat diet led to the development of fatty liver and a significant decrease in mtDNA-CN. A further 2 weeks of high-fat diet consumption resulted in a significant decrease in hepatic mtDNA-CN, despite the absence of fatty liver development, and a similar trend was observed for blood. Complementary in vitro experiments revealed that pharmacologically induced mitochondrial dysfunction led to a significant reduction in mtDNA-CN and was associated with increases in intracellular lipid accumulation in HepG2 cells.

Conclusions: Our findings suggest that reduced mtDNA-CN may contribute causally to SLD development and could serve as a convenient, noninvasive biomarker for early detection and risk assessment.

Background: Although the global COVID-19 mortality rate is decreasing, COVID-19 remains an infectious disease with a high mortality rate, especially in older adults and individuals with comorbidities. In Japan, mask-wearing has been left to individual discretion since March 13, 2023, but remains a key protective measure. This study aimed to identify factors influencing individual mask-wearing behavior in post COVID-19 era, with a focus on risk factors for severe COVID-19.

Methods: Data from 33,000 participants, obtained from the Japan COVID-19 and Society Internet Survey 2023, were used, which was conducted from September 25 to November 17, 2023. Participants were randomly selected from approximately 2.2 million panelists from a nationwide Japanese Internet research company, with sampling adjusted by age, sex, and living area to match the population distribution in Japan. The association between wearing a mask and risk factors for severe COVID-19 (age, sex, smoking, COVID-19 vaccination, history of COVID-19, body mass index (BMI), and comorbid conditions) was evaluated using univariate and multivariate analyses.

Results: In total, 28,481 individuals were included, of whom 18,371 (64.5%) answered that they wore masks. After adjusting for confounders, older age (adjusted relative risk [RR], 1.50; 95% confidence interval [CI], 1.45–1.55 for “75–83” years), no history of COVID-19 (adjusted RR, 1.06; 95% CI, 1.04–1.08), low BMI (adjusted RR, 1.04; 95% CI, 1.02–1.07), and increased number of comorbid conditions (adjusted RR, 1.11; 95% CI, 1.05–1.18 for three or more) were significant positive factors for wearing a mask. In contrast, men (adjusted RR, 0.89; 95% CI, 0.87–0.90), no COVID-19 vaccination (adjusted RR, 0.78; 95% CI, 0.76–0.81), and current smoking history (adjusted RR, 0.96; 95% CI, 0.93–0.99) were significant negative factors.

Conclusion: We demonstrated that mask-wearing behavior differed based on individual risk factors for severe COVID-19, with some risk factors negatively influencing mask use in Japan. It may be necessary to recommend mask-wearing for these individuals, especially during situations such as COVID-19 epidemic season or the onset of epidemics, considering individual mask-wearing behavior.

Background: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear.

Method: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing.

Results: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: −7.43% to −1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = −2.06%, 95% CI: −4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = −0.95, 95% CI: −1.23 to −0.66), while no significant link was found with D-loop methylation (β = −0.05, 95% CI: −0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect.

Conclusions: These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.

Although salt-related behaviors may influence urinary salt excretion in early childhood, this relationship remains unclear. This study aimed to examine salt-related behaviors using data from a salt check sheet and urinary salt excretion parameters using spot urine samples from 4-year-old children. This cross-sectional study included all 4-year-old children who underwent health checkups in Ohnan Town, Shimane Prefecture. The study sample consisted of 109 children (49 boys). Measures from spot urine samples included estimated salt excretion (g/day) and the sodium-potassium (Na/K) ratio. Salt-related behaviors were assessed using a salt check sheet that was completed by the parents or guardians. The associations between salt-related behaviors and urinary salt excretion parameters were analyzed using a generalized linear model. The median (M) and interquartile range (IQR) for urinary measures in 4-year-old children were as follows: estimated salt excretion (M = 4.4, IQR: 3.3–6.2) and Na/K ratio (M = 2.3, IQR: 1.4–3.3). The low frequency of consumption of high-salt foods (“such as pickles, pickled plums, etc.” and “noodles such as udon and ramen”) was associated with low salt excretion and low Na/K ratio. However, in the case of “consumption of udon, ramen, or other soups”, the Na/K ratio was higher for “About half a bowl” and “Some” than for “An entire bowl.” Additionally, for “eating out or having convenience-store-bought bento (lunch plate) for lunch”, the Na/K ratio was higher for “No” than for “Almost every day.” In conclusion, the frequency of high-sodium food intake was associated with both urinary sodium excretion and the Na/K ratio in 4-year-old children. Longitudinal investigations using the 24-hour urine collection method are needed to confirm these salt-related behaviors.

Background: Previous evidence showed that ambient air pollution and cardiovascular mortality are related. However, there is a lack of evidence towards the modification effect of long-term lifestyle on the association between short-term ambient air pollution and death from cardiovascular events.

Method: A total of 14,609 death from major adverse cardiovascular events (MACE) were identified among the China Kadoorie Biobank participants from 2013 to 2018. Ambient air pollution exposure including particulate matter 2.5 (PM_2.5), SO₂, NO₂, CO, and O₃ from the same period were obtained from space-time model reconstructions based on remote sensing data. Case-crossover design and conditional logistic regression was applied to estimate the effect of short-term exposure to air pollutants on MACE mortality.

Results: We found MACE mortality was significantly associated with PM_2.5 (relative percent increase 2.91% per 10 µg/m³ increase, 95% CI 1.32–4.53), NO₂ (5.37% per 10 µg/m³ increase, 95% CI 1.56–9.33), SO₂ (6.82% per 10 µg/m³ increase, 95% CI 2.99–10.80), and CO (2.24% per 0.1 mg/m³ increase, 95% CI 1.02–3.48). Stratified analyses indicated that drinking was associated with elevated risk of MACE mortality with NO₂ and SO₂ exposure; physical inactivity was associated with higher risk of death from MACE when exposed to PM_2.5; and people who had balanced diet had lower risk of MACE mortality when exposed to CO and NO₂.

Conclusions: The study results showed that short-term exposure to ambient PM_2.5, NO₂, SO₂, and CO would aggravate the risk of cardiovascular mortality, yet healthy lifestyle conduct might mitigate such negative impact to some extent.

Background: Exposure to environmental noise may have a negative impact on a population’s mental health. We estimated the prevalence of exposure perception to high environmental noise in the Valencian Community, a region on the Mediterranean coast of Spain, and analysed its association with poor mental health risk, adjusting for demographic, socioeconomic and health status variables.

Methods: Cross-sectional study based on a sample of 5.485 subjects, aged 15 or above, of the 2016 Valencian Community Health Survey. The risk of poor mental health was assessed via Goldberg’s questionnaire, a highly standardized self-reported questionnaire designed to screen for general psychological distress in the general population. Noise perception were determined in the home environment based on individuals’ responses to the Valencian Survey question about external noise problems. Sociodemographic variables, such as sex, age, level of education, or country of birth, and health variables, such as self-perceived health, or chronic diseases, were also considered. Logistic regression was used to estimate the Odds Ratios and confidence intervals of association between variables according to sex.

Results: The prevalence of poor mental health was 26.2% [n = 2665; 95% CI: 24.5–27.9] in men and 33.6% [n = 2820; 95% CI: 31.9–35.3] in women. A total of 7.8% [n = 5485; 95% CI: 6.8–8.8] presented exposure to high noise perception, with no differences according to sex. Being at risk of poor mental health was significantly associated (p < 0.05) with high noise perception after adjusting for the rest of the variables (OR: 2.16 [95% CI: 1.46–3.19] in men; 2.46 [95% CI: 1.72–3.50] in women).

Conclusions: Although the prevalence of exposure perception to high noise was not very high, population subgroups presenting high values were detected. High noise perception was related to the risk of poor mental health, regardless of other variables. Poor mental health risk was associated with exposure perception to high noise, other socioeconomic determinants, and health status. Improving noise exposure conditions could reduce the risk of poor mental health.