Age-related disruption of microvascular endothelium exacerbates hypertension and sarcopenia; and atherosclerosis is a well-known biological response to vascular endothelial injury. Therefore, prevalence of atherosclerosis among hypertensive elderly subjects may partly indicate the presence of an appropriate response to endothelial injury. We conducted a cross-sectional study of 795 elderly hypertensive Japanese subjects aged 60-89 years. Since platelet level is an indicator of vascular repair activity, subjects were stratified by platelet counts. No significant association between handgrip strength and subclinical carotid atherosclerosis (carotid intima-media thickness (CIMT) ≥1.1mm) was observed for subjects with lower platelet counts, while a significant positive association was observed for subjects with higher platelets. Adjusted odds and 95% confidence intervals of subclinical carotid atherosclerosis for 1 standard deviation increments in handgrip strength were 0.86 (0.61, 1.22) for subjects with lower platelets and 1.82 (1.26, 2.64) for subjects with higher platelets. A positive association between handgrip strength and subclinical carotid atherosclerosis exists in hypertensive elderly subjects with higher, but not lower, platelet counts. These results lead us to speculate that subjects with a beneficial influence on prevention of sarcopenia (maintenance of handgrip strength) may possess the capacity of active endothelial repair that causes atherosclerosis.

Background: Although many observational studies have demonstrated significant relationships between obesity and cardiometabolic traits, the causality of these relationships in East Asians remains to be elucidated.Methods: We conducted individual-level Mendelian randomization (MR) analyses targeting 14,083 participants in the Japan Multi-Institutional Collaborative Cohort Study, and two-sample MR analyses using summary statistics based on genome-wide association study data from 173,430 Japanese. Using 83 body mass index-related loci, genetic risk scores (GRS) for BMI were calculated, and the effects of BMI on cardiometabolic traits were examined for individual-level MR analyses by the two-stage least squares estimator method. The β-coefficients and standard errors for the per-allele association of each single-nucleotide polymorphism as well as all outcomes, or odds ratios with 95% confidence intervals were calculated in the two-sample MR analyses.Results: In individual-level MR analyses, the GRS of BMI was not significantly associated with any cardiometabolic traits. In two-sample MR analyses, higher BMI was associated with higher risks of higher blood pressure, triglycerides, uric acid, lower high-density-lipoprotein cholesterol and eGFR. The associations of BMI with type 2 diabetes in two-sample MR analyses were inconsistent by different methods, including the directions.Conclusions: The results of this study suggest that, even among the Japanese, an East Asian population with low levels of obesity, higher BMI could be causally associated with the development of a variety of cardiometabolic traits. Causality in those associations should be clarified in future studies with larger populations, especially those of BMI with type 2 diabetes.

Background: Stress coping strategies are related to health outcomes. However, there is no clear evidence for sex differences between stress-coping strategies and mortality. We investigated the relationship between all-cause mortality and stress-coping strategies, focusing on sex differences among Japanese adults.Methods: A total of 79,580 individuals aged 35–69 years participated in the Japan Multi-Institutional Collaborative Cohort Study between 2004 and 2014 and were followed up for mortality. The frequency of use of the five coping strategies was assessed using a questionnaire. Sex-specific, multivariable-adjusted hazard ratios (HRs) for using each coping strategy “sometimes,” and “often/very often” (versus “very few” use) were computed for all-cause mortality. Furthermore, relationships were analyzed in specific follow-up periods when the proportion assumption was violated.Results: During the follow-up (median: 8.5 years), 1,861 mortalities were recorded. In women, three coping strategies were related to lower total mortality. The HRs (95% confidence intervals) for “sometimes” were 0.81 (0.67–0.97) for emotional expression, 0.79 (0.66–0.95) for emotional support-seeking, and 0.80 (0.66–0.98) for disengagement. Men who “sometimes” used emotional expression and sometimes or often used problem-solving and positive reappraisal had a 15–41% lower HRs for all-cause mortality. However, those relationships were dependent on the follow-up period. There was evidence that sex modified the relationships between emotional support-seeking and all-cause mortality (p for interaction = 0.03).Conclusions: In a large Japanese population, selected coping strategies were associated with all-cause mortality. The relationship of emotional support-seeking was different between men and women.

Objectives: Existing studies of fathers’ involvement in childcare have focused on its impact on children’s psychosocial development and the facilitation of family functions, like marital relationships. In this study, we investigated the factors that determine paternal childcare in Japan, particularly focusing on work-related hours and environment, separately, according to mothers’ employment status. Methods: We used data from the Longitudinal Survey of Newborns in the 21st Century (2010 cohort) conducted in Japan. We restricted the sample to 27 783 participants with working fathers and analyzed how paternal work-related factors affect fathers’ childcare involvement by mothers’ employment status using an ordered logistic regression model. Results: In the model adjusting for all covariates, the odds ratio (OR) of spending less time with children on weekdays was higher: for fathers who worked 50 and more hours per week compared with those who worked 40-49 hours per week (OR = 1.95, 95% CI: 1.72-2.20 for 50-59 hours), for fathers whose commuting hours were longer than those commuting less than 0.5 hours per day (OR = 2.93, 95% CI: 2.34-3.69 for 1.5 or more hours), for larger workplace employee sizes than for 5-99 employee sizes (OR = 1.56, 95% CI: 1.38-1.77 for 500 or more employees). The associations between these paternal work-related variables and paternal hours spent with the children on weekdays were almost the same if the mothers were working or not working. Conclusions: Regardless of whether the mother is working, fathers’ work environment factors, such as working hours, play a key role in their involvement in childcare.

Background: Environmental and genetic factors are suggested to exhibit factor-based association with HDL-cholesterol (HDL-C) levels. However, the population-based effects of environmental and genetic factors have not been compared clearly. We conducted a cross-sectional study using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study to evaluate the population-based impact of smoking, drinking, and genetic factors on low HDL-C.Methods: Data from 11,498 men and women aged 35-69 years were collected for a genome-wide association study (GWAS). Sixty-five HDL-C-related SNPs with genome-wide significance (P < 5 × 10-8) were selected from the GWAS catalog, and seven representative SNPs were defined, and the population-based impact was estimated using population attributable fraction (PAF).Results: We found that smoking, drinking, daily activity, habitual exercise, egg intake, BMI, age, sex and the SNPs CETP rs3764261, APOA5 rs662799, LIPC rs1800588, LPL rs328, ABCA1 rs2575876, LIPG rs3786247, and APOE rs429358 were associated with HDL-C levels. The gene-environmental interactions on smoking and drinking were not statistically significant. The PAF for low HDL-C was the highest in men (63.2%) and in rs3764261 (31.5%) of the genetic factors, and the PAFs of smoking and drinking were 23.1% and 41.8%, respectively.Conclusions: The present study showed that the population-based impact of genomic factor CETP rs3764261 for low HDL-C was higher than that of smoking and lower than that of drinking.

Background: Staying active in daily life is believed to help maintain individuals' oral motor function and prevent oral frailty, a potential risk factor for general health. However, there is limited epidemiological evidence of this association. This study focused on vocalising frequency as an indicator of activeness in daily life.Methods: We conducted a home‐visit survey targeting residents aged ≥ 65 years in a rural community in the Goto Islands, Japan. Among 563 participants, those with missing data for the main outcome or vocalising (n = 84) were excluded. Tongue pressure was measured thrice; we used maximum tongue pressure as a marker of tongue motor function. Frequency of conversation, laughter and other vocalising opportunities (e.g., singing or Buddhist chanting) was measured. The multivariate‐adjusted regression models were used to calculate parameter estimates (B) for tongue pressure according to the frequency of vocalisation.Results: Among the 479 participants, the proportion of individuals who answered ‘every day’ was 77% for conversation, 48% for laughter and 47% for other vocalising opportunities. Participants engaging every day in other vocalising opportunities recorded higher maximum tongue pressure (B = 2.26; p = 0.03) than those who did not at all. Sex did not affect this association (p interaction = 0.72). Conversation and laughter every day overlapped with the everyday category of other vocalising opportunities, but they were not associated with tongue pressure.Conclusion: Engaging every day in vocalising opportunities other than conversation or laughter was independently associated with a higher maximum tongue pressure in older adults than those who vocalised less often.