Journal of Epidemiology最新文献

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: Healthy life expectancy (HLE) is a population health indicator that is widely used in developed countries, but little is known about its relationships with combinations of non-communicable disease risk factors. This study was conducted to examine HLE at age 65 years according to combinations of blood pressure levels, body mass index, smoking status, and diabetes mellitus (DM) in a Japanese population.

Methods: In a nationwide cohort study (NIPPON DATA90), data on these risk factors were obtained from participants in 1990 through physical examinations, blood tests, interviews, and questionnaires. Subsequently, participants aged ≥65 years underwent surveys on activities of daily living in 1995 and 2000, and multistate life tables were used to calculate combination-specific HLEs and their 95% confidence intervals (CIs).

Results: The study population comprised 6,569 participants (men: 2,797; women: 3,772) who were followed until 2010. HLE at age 65 years in men with grade II/III hypertension, obesity, current smoker status, and DM (HLE 12.9; 95% CI, 12.9-13.0 years) was 9.7 years shorter than men without these risk factors (HLE 22.6; 95% CI, 22.4-22.8 years). Similarly, HLE at age 65 years in women with grade II/III hypertension, obesity, current smoker status, and DM (HLE 16.2; 95% CI, 15.9-16.5 years) was 10.1 years shorter than women without these risk factors (HLE 26.3; 95% CI, 26.3-26.3 years).

Conclusion: The large discrepancies in HLEs underscore the impact of non-communicable disease risk factors, which should be considered when formulating health interventions to improve HLE in Japanese older adults.

Background: Studies have shown that informal caregiving is associated with an increased risk of cardiovascular diseases. However, there is limited evidence on the mechanisms involved. To fill this knowledge gap, we investigated the association of informal caregiving with changes in health-related behaviors.

Methods: We analyzed a nationally representative sample aged 50-59 years as of 2005 using fifteen waves of the Longitudinal Survey of Middle-Aged and Older Adults, which was conducted between 2005-2019. We investigated the association between the change in informal caregiving status and the change in health-related behaviors, including (1) heavy drinking, (2) smoking, (3) no exercise habits, and (4) no attendance at annual health checkups. We used multivariable logistic regression models with correlated random effects, adjusting for individual-level time-invariant characteristics.

Results: Among 268,165 observations from 30,530 participants (median age 55; interquartile range, 52-57 years at baseline; 51.6% women), 32,164 (12.0%) observations from 10,224 individuals provided informal care. After adjusting for potential confounders, informal caregiving was associated with higher probabilities of deteriorating health-related behaviors, including heavy drinking (adjusted odds ratio [aOR] 1.16; 95% confidence interval [CI], 1.03-1.32; adjusted P = 0.032) and no exercise habits (aOR 1.09; 95% CI, 1.04-1.15; adjusted P < 0.001). We observed similar patterns for smoking (aOR 1.12; 95% CI, 1.001-1.26; adjusted P = 0.053) and no attendance at health checkups (aOR 1.05; 95% CI, 0.999-1.10; adjusted P = 0.053).

Conclusion: This study showed that the transition into informal caregiving was associated with deteriorating cardiovascular-related health behaviors in Japan. These findings highlighted the importance of continued efforts to prevent the deterioration of caregivers' health-related behaviors.

Background: Poor dietary habits are a significant changeable factor contributing to negative health effects; however, the connection between variations in dietary diversity over time and mortality remains uncertain. This study aimed to evaluate the association between longitudinal changes in the dietary diversity score (DDS) and mortality in Japanese adults.

Methods: This prospective study included 20,863 adults (13,144 women, 7,719 men) aged 40-79 years from the Japan Collaborative Cohort Study. The DDS was evaluated twice, once at baseline and again 5 years later, using a validated food frequency questionnaire that assessed 33 food items. Participants were classified into four groups based on mean DDS: baseline low DDS/5 years later low DDS (n = 7,866; Low/Low group), baseline low DDS/5 years later high DDS (n = 2,951; Low/High group), baseline high DDS/5 years later low DDS (n = 3,000; High/Low group), and baseline high DDS/5 years later high DDS (n = 7,046; High/High group). Survival data were collected until 2009, and hazard ratios (HRs) for mortality were calculated using a Cox proportional hazards model.

Results: During a median follow-up of 14.8 years (256,277 person-years), 2,995 deaths were documented. After adjusting for confounders, participants in the High/High group had a lower HR for mortality from all causes (HR 0.82; 95% confidence interval [CI], 0.74-0.91) and cardiovascular disease (HR 0.81; 95% CI, 0.67-0.98) than those in the Low/Low group. Similar associations were observed with dairy, soy, and vegetables/fruits, but they were validated exclusively in women.

Conclusion: This study showed that maintaining a higher DDS may be associated with lower mortality in women.

Background: While evidence from Western countries links low-to-moderate alcohol consumption to a lower risk of type 2 diabetes mellitus (T2D), findings have been inconsistent in Asia. Since T2D in Asia involves both insulin resistance and deficient insulin secretion, both of which are differently affected by alcohol, we prospectively examined whether the association differs according to body mass index (BMI) categories among the Japanese.

Methods: Participants were 31,524 health checkup examinees (26,819 males and 4,705 females aged 20-64 years) who were free from diabetes at baseline. Self-reported data on alcohol use were used to estimate the average daily alcohol consumption at the baseline. Incident diabetes was identified at annual checkups during the follow-up period. A Cox proportional hazards model was used to estimate hazard ratios and 95% confidence intervals.

Results: During a median follow-up of 12.0 years, 3,527 male and 287 female participants developed T2D. The association between alcohol consumption and T2D risk differed markedly by BMI in both sexes. Among males, low- and moderate-level alcohol consumption was associated with a lower T2D risk in individuals with BMI ≥25.0 kg/m², whereas consumption at a level of 2 go/day (approximately 46 g ethanol) was linked to an increased T2D risk in those with BMI ≤22.0 kg/m². In females, similar patterns were observed, although confidence intervals were broad due to the smaller sample size.

Conclusion: In Japan, low-to-moderate alcohol consumption may lower T2D risk in those with excess body weight, while high alcohol consumption may increase T2D risk in those with lower BMI.

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: 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.