Associations of overweight and obesity with the risk of cardiovascular disease according to metabolic risk factors among middle-aged Japanese workers: The Aichi Workers' cohort study.

BACKGROUND: The association between obesity and cardiovascular disease (CVD) remains unclear, particularly for those with established CVD risk factors. We analyzed follow-up data from the Aichi Workers' Cohort Study. We studied the association between the degree of obesity and risk of CVD and its subtypes specifically among individuals with hypertension, hyper-low-density lipoprotein (LDL)-cholesterolemia, or diabetes. METHODS: Pooled data of 8972 adults (7076 men and 1896 women) who were recruited between 2002 and 2008 were used in the current analysis. We used multivariable Cox proportional hazard model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between the degree of obesity assessed with body mass index (BMI) and the risk of CVD and its subtypes, i.e., coronary heart disease (CHD) and stroke. RESULTS: During a median of 12 years, there were 197 CVDs (80 CHDs and 117 strokes). BMI ≥ 27.5 compared to 21.0-22.9 kg/m2 was positively and significantly associated with the risks of CVD, CHD, and total stroke. Hypertension, hyper-LDL-cholesterolemia, and diabetes mediated 15.9%, 5.8%, and 8.7% of obesity-CVD associations, respectively, and 28.3% by their combination. In the stratified analyses by the presence of risk factors, BMI ≥ 25.0 (overweight/obesity) compared to BMI < 25 kg/m2 was associated with a higher risk of CVD in those with and without hypertension, but only with hyper-LDL-cholesterolemia, and without diabetes. CONCLUSIONS: Overweight/obesity was associated with the risk of CVD and its subtypes. About 30% of the risk was explained by hypertension, hyper-LDL-cholesterolemia, and diabetes, of which hypertension accounted for approximately the half of the explained risk. However, overweight/obesity increased the risk of CVD even in those without hypertension. These findings highlight the importance of controlling and preventing overweight/obesity regardless of chronic disease status.

Nonrestorative Sleep and Type 2 Diabetes Incidence: the Aichi Workers' Cohort Study.

BACKGROUND: The term "nonrestorative sleep (NRS)" refers to unrefreshed feeling at wake-up and is a domain of poor sleep quality. Previous researches have demonstrated that NRS is linked to a number of diseases and adverse health outcomes, but less is known regarding the link between NRS and diabetes, particularly in Japanese. METHODS: We studied 3665 middle-aged male participants of the Aichi Workers' Cohort Study who were followed-up from 2002 to 2019. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of incident type 2 diabetes mellitus (T2DM) in relation to NRS adjusted for potential confounding variables. RESULTS: During a median follow-up of 14.6 years, 421 type 2 diabetes cases were identified. Participants with NRS had a higher crude incidence rate of T2DM (11.2/1,000 person-years), compared to participants without NRS (9.3/1,000 person-years). In the fully adjusted model, individuals who reported having NRS had a significantly higher risk of developing T2DM (HR: 1.36, 95% CI: 1.10-1.67). The association was observed only in participants under 50 years old (HR: 1.82, 95% CI: 1.36-2.43), not in the older (50 years or older) participants (P for interaction =0.025). In contrast, stratified analyses by the presence of shift work, obesity or sleep duration showed similar associations in all the strata. CONCLUSIONS: NRS was associated with higher risk of T2DM in middle-aged Japanese male workers independent of a variety of lifestyle factors and other sleep problems.

Association of psychological factors with advanced-level functional competency: Findings from the Aichi workers' cohort study, 2002-2019.

Objective: This study examined the longitudinal association of perceived stress, ikigai, and having someone one can count on in middle age with the advanced-level functional competency in older age, which is crucial for the maintenance of independent life among older adults. The issue is especially relevant in super-aged countries like contemporary Japan, where more and more older people live in a household consisting only of older people. Methods: Data were collected in 2019 from a total of 1692 retirees of the Aichi Workers' Cohort Study participants in which baseline survey including psychological factors was conducted during their employment in 2002. Japan Science and Technology Agency Index of Competence (JST-IC) was used to measure the advanced-level functional competency. Multivariable-adjusted odds ratios (ORs) were obtained for having low JST-IC in later life by the degrees of psychological factors reported in the middle age adjusting for the presence of depressive mood in 2019. Results: Those who were not sure about ikigai (OR: 2.02, 95 % CI: 1.33 to 3.08) and who have no one to count on (OR: 2.19, 95 % CI: 1.52 to 3.16) in the middle age were significantly associated with low JST-IC after retirement. Having much stress was significantly inversely associated with a low JST-IC (OR: 0.69, 95 % CI: 0.50 to 0.97). Conclusion: Having ikigai and someone reliable, and stress during middle age might play a role in preventing impaired advanced-level functional competency. Improved ikigai and increased social interaction and support might improve functional competency. Further research might explore avenues for improving ikigai.

Good death for people living with dementia: a qualitative study.

BACKGROUND: Ensuring a good death is one of the primary objectives of palliative care and end-of-life care. There is insufficient evidence regarding what defines a good death for people living with dementia. Obtaining an understanding of what constitutes a good death could help improve dementia care. This study aimed to explore how multiple stakeholders perceive a good death for people living with dementia. METHODS: This qualitative study was carried out across six prefectures in Japan. Enrollment of participants took place within dementia outpatient clinics, hospitals, daycare centers, and community centers. A total of thirty-three in-depth interviews with people living with dementia, physicians, and nurses were conducted. Six focus group discussions were performed with family caregivers and care workers. Verbatim transcripts of the interviews were prepared, and inductive content analysis was used to examine the data. FINDINGS: Regarding the perception of a good death, the following themes were derived: (1) painless death; (2) dying in a preferred environment; (3) family's coping with loss; (4) maintaining regular life; (5) living with respect; and (6) preparation for death. All these themes are interrelated. Participants viewed a good death as a process rather than a single event. CONCLUSION: This study identifies crucial components of a good death for people living with dementia. The findings could be used to improve dementia care.

Association of Low-Density Lipoprotein Cholesterol with Risk of Coronary Heart Disease and Stroke among Middle-Aged Japanese Workers: An Analysis using Inverse Probability Weighting.

AIMS: The associations between low-density lipoprotein cholesterol (LDL-C) and the risk of cardiovascular disease (CVD) subtypes are not well established among the Japanese population. This study used longitudinal data from the Aichi Workers' Cohort Study to explore the association between LDL-C levels and the risk of coronary heart disease (CHD) and stroke subtypes. METHODS: Pooled data of 8966 adults (7093men and 1903 women) who were recruited between (2002) and (2008) were used for the current analysis. Propensity scores for the LDL-C categories were generated using multinomial logistic regression. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated from the inverse probability weighted Cox proportional hazards model for LDL-C category associations with risks of CHD, stroke subtypes, and CVD. RESULTS: During a median follow-up of 12 years, 122 strokes (57 ischemic strokes, 25 intracerebral hemorrhage, and 40 unknown subtypes) and 82 cases of CHD were observed. LDL-C 160- mg/dL compared to LDL-C 100-119 mg/dL was positively and significantly associated with the risk of CHD (HR: 4.56; 95% CI: 1.91-10.9) but not with ischemic stroke (HR: 0.99; 95% CI: 0.44-2.22). LDL-C was inversely associated with the risk of intracerebral hemorrhage (P for trend=0.009). CONCLUSION: In middle-aged Japanese workers, LDL-C was significantly and positively associated with CHD, but not with ischemic stroke. LDL-C was inversely significantly associated with intracerebral hemorrhage.

Long-term variability and change trend of systolic blood pressure and risk of type 2 diabetes mellitus in middle-aged Japanese individuals: findings of the Aichi Workers' Cohort Study.

Studies have reported that short-term blood pressure (BP) variability (BPV) is associated with type 2 diabetes mellitus (T2DM) incidence, but the association with long-term BPV remains unclear. The present study investigated the associations of long-term BPV as well as the time trend of BP changes over time with the incidence of T2DM. This study followed a cohort of 3017 Japanese individuals (2446 male, 571 female) aged 36-65 years from 2007 through March 31, 2019. The root-mean-square error (RMSE) and the slope of systolic BP (SBP) change regressed on year were calculated individually using SBP values obtained from 2003 to baseline (2007). A multivariable Cox proportional hazard model was applied to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for tertiles of SBP RMSE and continuous SBP slopes adjusted for age, sex, smoking status, regular exercise, sodium intake, family history of diabetes, sleep disorder, body mass index (BMI), SBP, and fasting blood glucose (FBG) at baseline, and BMI slope from 2003 to 2007. The highest RMSE tertile compared to the lowest was associated with a significantly higher incidence of T2DM after adjusting for covariates (HR: 1.79, 95% CI: 1.15, 2.78). The slope was also significantly associated with T2DM incidence until baseline SBP and FBG were adjusted (HR: 1.03, 95% CI: 0.99, 1.07). In conclusion, long-term SBP variability was significantly associated with an increased incidence of T2DM independent of baseline age, sex, BMI, SBP, FBG, lifestyle factors and BMI slope from 2003 until baseline.