Background: The interaction and substitution effects of physical activity (PA) and sitting time (ST) living in non-western countries have not been well investigated. This study aimed to examine the association of moderate-to-vigorous physical activity (MVPA) and ST with disability and mortality in older adults.

Methods: This prospective study analyzed data from 10,164 adults aged over 65 years who participated in the Kyoto-Kameoka study in Japan. We evaluated MVPA and ST using the validated International Physical Activity Questionnaire-Short Form. Participants were categorized into four groups based on their levels of MVPA (150 min/week) and ST (300 min/day): low MVPA/high ST, low MVPA/low ST, high MVPA/high ST, and high MVPA/low ST. Outcomes were gathered between July 30, 2011, and November 30, 2016.

Results: Over a median follow-up of 5.3 years (45,461 person-years), 2,273 disability cases were documented. The low MVPA/high ST groups were associated with higher disability risk than those in the high MVPA/low ST groups (hazard ratio [HR] 1.52; 95% confidence interval [CI], 1.31–1.75), and the interaction between MVPA and ST accounted for 48.5% of the relative excess risk of disability in the low MVPA/high ST group (P for interaction = 0.006). Daily replacement of 10 minutes of ST with 10 minutes of MVPA was associated with a reduced risk of disability (HR 0.980; 95% CI, 0.971–0.989) and all-cause mortality (HR 0.975; 95% CI, 0.962–0.988).

Conclusion: These findings indicate that even a small substitution of ST with MVPA could help lower both the risk of disability and mortality.

Background: The discomfort experienced due to residual tobacco smoke, a form of thirdhand smoke exposure brought into workplaces by smokers, and its health impacts on non-smokers have been inadequately investigated. This study explored associations between non-smokers’ discomfort and work performance and mental health.

Methods: This observational internet-based survey was conducted in 2021 as part of the Japan Society and New Tobacco Internet Survey. Participants comprised 6,519 adult workers without firsthand or secondhand smoking. Work performance and mental health were evaluated using the Work Functioning Impairment Scale (WFun) and Kessler Psychological Distress Scale (K6), respectively. The proportion of participants who experienced discomfort from the residual tobacco smoke in their workplace by smokers in the previous year was calculated according to the workplace’s smoke-free policy, and the difference was assessed using the χ² test. The association between such discomfort and WFun and K6 scores was examined using univariable and multivariable logistic regression analyses.

Results: Among respondents, 17.1% reported experiencing discomfort due to the residual tobacco smoke. A strict smoke-free workplace policy was associated with a lower proportion of respondents experiencing such discomfort (P < 0.001). Those who experienced discomfort more frequently had significantly higher scores on the WFun (15.5% “never”, 21.3% “sometimes”, 26.2% “frequently”) and K6 (37.8% “never”, 48.2% “sometimes”, 50.8% “frequently”). Adjusting for potential covariates in multivariable analyses did not change these results.

Conclusion: Discomfort from thirdhand smoke was associated with worse work performance and mental health problems. Promotion of strict smoke-free workplace policies is required to reduce such experiences.

Background: We examined the association between the coronavirus disease 2019 (COVID-19)-specific prefectural bed utilization rate and in-hospital mortality during the first 3 years of the pandemic in Japan.

Methods: This nationwide study included 58,175 COVID-19 patients from the COVID-19 Registry Japan, hospitalized between May 1, 2020 and November 30, 2022. Based on the weekly COVID-19-specific bed utilization rate in each prefecture at diagnosis, patients were categorized into four groups (<25%, 25% to <50%, 50% to <75%, and ≥75%). Odds ratios (ORs) were estimated by fitting a generalized linear mixed model with prefecture as a random intercept and adjusting for covariates (age, gender, body mass index, smoking and drinking status, and comorbidities). Additional analyses according to age group, gender, and wave of the pandemic were conducted.

Results: We observed 2,312 (4.0%) all-cause in-hospital deaths. All-cause in-hospital mortality increased with higher COVID-19 bed utilization rates at diagnosis (OR for multivariable model 1.35; 95% confidence interval [CI], 1.19–1.54 for 25% to <50%; OR 1.89; 95% CI, 1.66–2.16 for 50 to <75%; OR 2.16; 95% CI, 1.80–2.58 for ≥75%; P for trend <0.0001). Stronger associations were noted among the younger population (aged <70 years: OR 3.18; 95% CI, 1.96–5.19) and during the fourth (March 1–June 30, 2021: OR 3.81; 95% CI, 2.13–6.80) and sixth pandemic waves (January 1–June 30, 2022: OR 2.67; 95% CI, 1.68–4.23).

Conclusion: Our results emphasize that preventing hospital bed shortages during outbreaks is an important public health strategy to reduce the associated mortality, particularly when new strains emerge and in younger people.

The Iodine Status in Pregnancy and Offspring Health Cohort (ISPOHC) was initiated in Shanghai to address the need for a comprehensive and longitudinal study on iodine nutrition and its effects on maternal and offspring health. The findings based on the Shanghai population can serve as a reference for other megacities experiencing significant dietary changes simultaneously. ISPOHC utilized a stratified cluster random sampling design, enrolling 5,099 pregnant women from all 16 districts of Shanghai. The survey has been conducted in three phases. Data collected at different time points include health status, living habits, dietary intake, birth, feeding, early development, anthropometric measurements, and biomarkers, allowing for an in-depth evaluation of iodine nutrition’s impact on offspring development. Data were collected through a combination of questionnaires, home visits, anthropometric measurements, and biological sample collection. The integration of detailed food investigation and on-site weighing of household seasonings provides a more precise assessment of dietary iodine intake, particularly iodized salt consumption, distinguishing this study. The study has provided significant insights into the relationship between iodine nutrition during pregnancy and various health outcomes.