Background: The Tohoku Medical Megabank Project has initiated the Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study) including genomic and omics investigations and conducted a self-administered food frequency questionnaire with the response option “constitutionally unable to eat or drink it” for individual food items (TMM-FFQ) for pregnant women. This study evaluated the validity of the TMM-FFQ among pregnant women.

Methods: Participants comprised 122 pregnant women aged ≥20 years residing in Miyagi Prefecture who completed weighed food records (WFRs) for 3 days as reference intake and the TMM-FFQ during mid-pregnancy. Correlations between nutrient or food group intakes based on the WFR and the TMM-FFQ were calculated using Spearman’s rank correlation coefficients (CCs), adjusting for energy intake and correcting for random within-individual variation of WFR. Cross-classification was also conducted according to quintiles using the WFR and TMM-FFQ data.

Results: The percentages of participants who chose the “constitutionally unable to eat or drink it” option were >3% for seven food and drink items. CCs were >0.30 for 31 nutrients; the median across energy and 44 nutrients was 0.41. CCs were >0.30 for 14 food groups; the median across 20 food groups was 0.35. The median percentages of cross-classification into exact plus adjacent quintiles and extreme quintiles were 63.1% and 3.3% for energy and nutrients and 61.9% and 4.1% for food groups, respectively.

Conclusion: The validity of the TMM-FFQ compared with the WFR was reasonable for certain nutrients and food groups among pregnant women in the TMM BirThree Cohort Study.

Background: Several studies reported an association between the number of teeth and the incidence of hip fractures in observational studies, mainly in middle-aged adults. This retrospective cohort study aimed to clarify the association between the number of teeth and the incidence of hip fractures.

Methods: In this retrospective cohort study, a total of 256,772 participants aged 75 years or older who underwent public dental checkups in Japan were evaluated. Exposure in this study was the number of teeth, with a maximum number of 28, excluding third molars. Outcome measures were the incidence of hip fractures needing surgery, using the Japanese procedure codes in medical claims.

Results: A total of 190,998 participants met the inclusion criteria and were available for analysis. Adjusted Fine and Gray models identified a significant association between the number of teeth, including sound, filled, and decayed teeth, and the incidence of hip fractures among women but not for men. The continuous net reclassification improvement of the sound and filled teeth count model increased by 0.078 compared with that of the sound, filled, and decayed teeth count model among women.

Conclusion: The number of sound and filled teeth predicted the risk of hip fractures in women, whereas no association was observed between the number of teeth and hip fractures in men.

Background: Studies on the association between multimorbidity and mortality in large populations have mainly been conducted in European and North American populations. This study aimed to identify the association between cardiometabolic multimorbidity and all-cause and cardiovascular disease (CVD) mortality in the Asia Cohort Consortium.

Methods: In this prospective cohort study, pooled analysis was performed to evaluate the association between cardiometabolic diseases (hypertension, diabetes, ischemic heart disease, and stroke), multimorbidity, and all-cause and CVD mortality, including premature mortality, among participants from 11 Asian cohort studies. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox hazard regression.

Results: A total of 483,532 participants were followed for a median of 14.3 years. Compared with participants without any disease, those with stroke and diabetes had higher age- and sex-adjusted HRs for all-cause mortality (HR 3.9; 95% CI, 3.28–4.56). Moreover, the age- and sex-adjusted HRs for CVD mortality were highest in participants with stroke, ischemic heart disease, and diabetes (HR 10.6; 95% CI, 6.16–18.25). These patterns remained consistent after additional adjustments for smoking status and body mass index. The risk of premature mortality followed similar trends but was more pronounced.

Conclusion: These findings highlight the differential impacts of individual cardiometabolic diseases and their combinations on mortality risks. Stroke and diabetes were associated with the highest risks for all-cause and cardiovascular mortality, underscoring the need for targeted prevention and personalized management strategies tailored to these high-risk conditions in Asian populations.

Background: Evidence of post-COVID-19 condition (PCC) in the Alpha- and Delta-variant dominant waves is limited.

Methods: In a nationwide multicenter cohort study in collaboration with 20 hospitals, we collected data using self-administered questionnaires and electronic medical records of participants aged 20 or more diagnosed with COVID-19, hospitalized between April 1, 2021 and September 30, 2021, and discharged alive. Descriptive statistics were analyzed for PCC and mental health (HADS anxiety and depression scores), comparing Alpha- and Delta-variant dominant waves.

Results: We analyzed 1,040 patients (median age, 57 [IQR 49–66] years; men, 66.2%). Of the respondents, 45.4% had at least one PCC symptom 1 year after infection. The common symptoms included dyspnea (20.7%), fatigue/malaise (17.6%), muscle weakness (15.4%), decrease in concentration (13.4%), and sleep disorder (13.3%), followed by brain fog (8.4%). Among patients with PCC, 14.0% had anxiety (HADS-Anxiety ≥11), and 18.6% had depression (HADS-Depression ≥11), with four times higher proportions than those without PCC; only small variations by age, sex, and waves were observed. Associated factors for PCC were age 40 years or over, women, severity of COVID-19 during hospitalization, ex-smokers who quit smoking before COVID-19 infection and being infected during the Delta-variant dominant wave.

Conclusion: The study described the prevalence of PCC, associated factors, and mental health of COVID-19 survivors hospitalized during the Alpha- and Delta-variant dominant waves in Japan. Further follow-up will be conducted to examine the longer-term impact of COVID-19 on PCC, complications, daily life, and socioeconomic status.

Background: We launched the Wako Cohort Study in 2023 to identify individual and socio-environmental factors related to the extension of healthy life expectancy and the reduction of health disparities among community-dwelling adults and to develop health promotion and care prevention strategies. This study profile aims to describe the study design and participants’ profile at baseline.

Methods: The Wako Cohort Study is a prospective study of community-dwelling adults aged ≥40 years living in Wako City, Saitama Prefecture, Japan. The Wako Cohort Study consists of two surveys: a mail-in survey for persons aged ≥40 years and a face-to-face assessment (on-site survey) for those aged ≥65 years. The survey items were designed considering the following points: 1) life course perspective (transition from middle to old age in the life course), 2) health indifference, and 3) employment in older age.

Results: A total of 8,824 individuals participated in the mail-in survey (2,395 persons aged 40–64 years and 6,429 aged ≥65 years). Of those aged ≥65 years who returned the mail survey, 1,004 participated in the subsequent on-site survey. Men aged ≥65 years tended to have higher health interests than those aged 40–64 years; however, this was not true for women. In the mail-in survey, 30.4% of those aged ≥65 years were employed.

Conclusion: The Wako Cohort Study is expected to provide new insights into the development of strategies to extend healthy life expectancy and reduce health disparities in Japan.