Paternal involvement in childcare and housework and mothers' spanking behavior: The Japanese longitudinal survey of newborns in the 21st century.

BACKGROUND: No previous study reported an association between paternal involvement in childcare and housework and maternal physical punishment. METHODS: Using data from the Japanese Longitudinal Survey of Newborns in the 21st century (N = 38,554), we analyzed responses about fathers' involvement in childcare and housework at 6 months and mothers' spanking of children at 3.5 years. Fathers' involvement in childcare and housework was scored and categorized into quartiles. Spanking frequency was asked in the "often", "sometimes", or "not at all" categories. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the mothers' often spanking children were computed for the fathers' involvement in childcare and housework. We also stratified the association by fathers' working hours (40-49, 50-59, or ≥ 60 hours/week). RESULTS: Among the 16,373 respondents, the proportion of mothers who often spanked their children was 4.8%. Compared with the lowest quartile, a higher frequency of paternal involvement in housework was associated with a lower risk of spanking children (p trend = 0.001). Adjustment for covariates attenuated the association, but significant association was observed in the 3rd quartile of paternal involvement in housework [OR (95% CI): 0.77 (0.62-0.96)]. When the fathers worked fewer than 50 hours a week, a significant negative association was observed between the fathers' frequency of childcare and the likeliness of the mothers' spanking their children (p trend = 0.02). CONCLUSIONS: The fathers' active involvement in childcare and housework could reduce the mothers' physical punishment for their children.

BMI and Cardiometabolic Traits in Japanese: A Mendelian Randomization Study.

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 (BMI)-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 using the two-stage least squares estimator method. The ß-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 increased risks of higher blood pressure, triglycerides, and uric acid, as well as lower high-density-lipoprotein cholesterol and eGFR. The associations of BMI with type 2 diabetes in two-sample MR analyses were inconsistent using different methods, including the directions. CONCLUSION: 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.

GWAS meta-analysis of kidney function traits in Japanese populations.

BACKGROUND: Genetic epidemiological evidence for the kidney function traits in East Asian population including Japanese remain still relatively unclarified. Especially, the number of GWASs for kidney traits reported still remains limited, and the sample size of each independent study is relatively small. Given the genetic variability between ancestries/ethnicities, implementation of GWAS with sufficiently large sample sizes in specific population of Japanese is considered meaningful. METHODS: We conducted the GWAS meta-analyses of kidney traits by leveraging the GWAS summary data of the representative large genome cohort studies with about 200,000 Japanese participants (n = 202,406 for estimated glomerular filtration rate [eGFR] and n = 200,845 for serum creatinine [SCr]). RESULTS: In the present GWAS meta-analysis, we identified 110 loci with 169 variants significantly associated with eGFR (on chromosomes 1-13 and 15-22; p < 5×10-8), whereas we also identified 112 loci with 176 variants significantly associated with SCr (on chromosomes 1-22; p < 5×10-8), of which one locus (more than 1Mb distant from known loci) with one variant (CD36 rs146148222 on chromosome 7) for SCr was considered as the truly novel finding. CONCLUSIONS: The present GWAS meta-analysis of largest genome cohort studies in Japanese provided some original genomic loci associated with kidney function in Japanese, which may contribute to the possible development of personalized prevention of kidney diseases based on genomic information in the near future.

Food group intakes and high-sensitivity C-reactive protein among community-dwelling Japanese adults: a cross-sectional study.

OBJECTIVE: Healthy dietary patterns have been linked to lower levels of chronic inflammation. The present study aimed to investigate the associations between food group intakes and high-sensitivity C-reactive protein (hsCRP) among community-dwelling adults. DESIGN: Cross-sectional. SETTING: Three areas in Japan (Shiga, Fukuoka, or Kyushu and Okinawa). PARTICIPANTS: The present analysis included 13 648 participants (5126 males and 8522 females; age range, 35-69 years) who had been enrolled in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. Food group intakes were estimated using a FFQ. Multiple linear regression was used to examine associations between the quartiles of each energy-adjusted food group intake and log-transformed hsCRP. RESULTS: The following concentration ratios of hsCRP after comparing the highest and lowest quartiles of food group intake were significant: in males, 1·12 (95 % CI 1·02, 1·22) for processed meat, 1·13 (95 % CI 1·03, 1·24) for fish and 0·83 (95 % CI 0·76, 0·90) for nuts; in females, 0·89 (95 % CI 0·81, 0·97) for bread, 1·11 (95 % CI 1·03, 1·19) for processed meat, 0·86 (95 % CI 0·80, 0·92) for vegetables, 1·19 (95 % CI 1·11, 1·29) for fruit, 0·90 (95 % CI 0·84, 0·97) for nuts and 0·88 (95 % CI 0·82, 0·95) for green tea. CONCLUSIONS: Processed meat and nut intakes were associated with higher and lower hsCRP levels, respectively, in both sexes. However, for several food groups, including fish and fruit, previous findings from dietary pattern analyses were not supported by the present analyses at the food group level.

Association between consumption of small fish and all-cause mortality among Japanese: the Japan Multi-Institutional Collaborative Cohort Study.

OBJECTIVE: Although small fish are an important source of micronutrients, the relationship between their intake and mortality remains unclear. This study aimed to clarify the association between intake of small fish and all-cause and cause-specific mortality. DESIGN: We used the data from a cohort study in Japan. The frequency of the intake of small fish was assessed using a validated FFQ. The hazard ratio (HR) and 95 % confidence interval (CI) for all-cause and cause-specific mortality according to the frequency of the intake of small fish by sex were estimated using a Cox proportional hazard model with adjustments for covariates. SETTING: The Japan Multi-Institutional Collaborative Cohort Study. PARTICIPANTS: A total of 80 802 participants (34 555 males and 46 247 females), aged 35-69 years. RESULTS: During a mean follow-up of 9·0 years, we identified 2482 deaths including 1495 cancer-related deaths. The intake of small fish was statistically significantly and inversely associated with the risk of all-cause and cancer mortality in females. The multivariable-adjusted HR (95 % CI) in females for all-cause mortality according to the intake were 0·68 (0·55, 0·85) for intakes 1-3 times/month, 0·72 (0·57, 0·90) for 1-2 times/week and 0·69 (0·54, 0·88) for ≥ 3 times/week, compared with the rare intake. The corresponding HR (95 % CI) in females for cancer mortality were 0·72 (0·54, 0·96), 0·71 (0·53, 0·96) and 0·64 (0·46, 0·89), respectively. No statistically significant association was observed in males. CONCLUSIONS: Intake of small fish may reduce the risk of all-cause and cancer mortality in Japanese females.

Differences in prevalence of self-reported oral hypofunction between older adult patients with rheumatoid arthritis and the general older population: A cross-sectional study using propensity score matching.

OBJECTIVE: To examine the association between rheumatoid arthritis (RA) and oral hypofunction (OHF) using propensity score matching (PSM) to adjust for differences between older adults with RA and the general older adult population. METHODS: We conducted a cross-sectional survey among 189 older adults with RA in 2019 (mean age, 71.9 ± 3.6) and 47 178 independent older adult residents in 2016 (mean age, 71.6 ± 4.0), respectively. The questionnaire covered information on socio-demographic characteristics and OHF for both groups. Age, sex, educational level and smoking history were used to determine PSM. Prevalence ratios (PRs) and 95% confidence intervals (CIs) of self-reported OHF (fewer remaining teeth, decreased masticatory function, deterioration of swallowing function and oral dryness) were estimated using Poisson regressions. RESULT: OHF was observed in 44.4% of patients with RA and 27.5% of residents. Before PSM, the prevalence of OHF among patients with RA was higher than that of residents (PR, 1.75; 95% CI, 1.50-2.05). After PSM, there were 189 patients with RA and residents, and the prevalence of OHF among patients with RA was still higher (PR, 1.61; 95% CI, 1.22-2.13). Poisson regression showed that the prevalence of 19 or fewer teeth (PR, 1.06; 95% CI, 0.82-1.36), difficulties eating tough foods (PR, 1.18; 95% CI, 0.90-1.55), difficulties swallowing tea or soup (PR, 1.77; 95% CI, 1.19-2.63), and dry mouth (PR, 2.79; 95% CI, 1.90-4.07) was higher among patients with RA than residents. CONCLUSION: Compared with the general older adult population, patients with RA have a higher prevalence of self-reported OHF.

Association of kidney function with cancer incidence and its influence on cancer risk of smoking: The Japan Multi-Institutional Collaborative Cohort Study.

The association between kidney function and cancer incidence is inconsistent among previous reports, and data on the Japanese population are lacking. It is unknown whether kidney function modifies the cancer risk of other factors. We aimed to evaluate the association of estimated glomerular filtration rate (eGFR) with cancer incidence and mortality in 55 242 participants (median age, 57 years; 55% women) from the Japan Multi-Institutional Collaborative Cohort Study. We also investigated differences in cancer risk factors between individuals with and without kidney dysfunction. During a median 9.3-year follow-up period, 4278 (7.7%) subjects developed cancer. Moderately low and high eGFRs were associated with higher cancer incidence; compared with eGFR of 60-74 ml/min/1.73 m2 , the adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) for eGFRs of ≥90, 75-89, 45-59, 30-44 and 10-29 ml/min/1.73 m2 were 1.18 (1.07-1.29), 1.09 (1.01-1.17), 0.93 (0.83-1.04), 1.36 (1.00-1.84) and 1.12 (0.55-2.26), respectively. High eGFR was associated with higher cancer mortality, while low eGFR was not; the adjusted subdistribution HRs (95% CIs) for eGFRs of ≥90 and 75-89 ml/min/1.73 m2 were 1.58 (1.29-1.94) and 1.27 (1.08-1.50), respectively. Subgroup analyses of participants with eGFRs ≥60 and <60 ml/min/1.73 m2 revealed elevated cancer risks of smoking and family history of cancer in those with eGFR <60 ml/min/1.73 m2 , with significant interactions. Our findings suggest that the relationship between eGFR and cancer incidence was U-shaped. Only high eGFR was associated with cancer mortality. Kidney dysfunction enhanced cancer risk from smoking.

Dietary Carbohydrate and Fat Intakes and Risk of Mortality in the Japanese Population: the Japan Multi-Institutional Collaborative Cohort Study.

BACKGROUND: Previous cohort studies have yielded contradictory findings regarding the associations of dietary carbohydrate and fat intakes with risks of mortality. OBJECTIVES: We examined long-term associations of carbohydrate and fat intakes with mortality. METHODS: In this cohort study, 34,893 men and 46,440 women aged 35-69 y (mean body mass index of 23.7 and 22.2 kg/m2, respectively) were followed up from the baseline survey (2004-2014) to the end of 2017 or 2018. Intakes of carbohydrate, fat, and total energy were estimated using a food frequency questionnaire. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for all-cause and cause-specific mortality according to percentage of energy intakes of carbohydrate and fat. RESULTS: During a mean 8.9-y follow-up, we identified 2783 deaths (1838 men and 945 women). Compared with men who consumed 50% to <55% of energy from carbohydrate, those who consumed <40% carbohydrate energy experienced a significantly higher risk of all-cause mortality (the multivariable-adjusted HR: 1.59; 95% CI: 1.19-2.12; P-trend = 0.002). Among women with 5 y or longer of follow-up, women with high-carbohydrate intake recorded a higher risk of all-cause mortality; the multivariable-adjusted HR (95% CI) was 1.71 (0.93-3.13) for ≥65% of energy from carbohydrate compared with that for 50% to <55% (P-trend = 0.005). Men with high fat intake had a higher risk of cancer-related mortality; the multivariable-adjusted HR (95% CI) for ≥35% was 1.79 (1.11-2.90) compared with that for 20% to <25%. Fat intake was marginally inversely associated with risk of all-cause and cancer-related mortality in women (P-trend = 0.054 and 0.058, respectively). CONCLUSIONS: An unfavorable association with mortality is observed for low-carbohydrate intake in men and for high-carbohydrate intake in women. High fat intake can be associated with a lower mortality risk in women among Japanese adults with a relatively high-carbohydrate intake.

GWAS of folate metabolism with gene-environment interaction analysis revealed the possible role of lifestyles in the control of blood folate metabolites in Japanese - the J-MICC Study.

BACKGROUND: The present genome-wide association study (GWAS) aimed to reveal the genetic loci associated with folate metabolites as well as to detect related gene-environment interactions in Japanese. METHODS: We conducted the GWAS of plasma homocysteine (Hcy), folic acid (FA), and vitamin B12 (VB12) levels in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study participants who joined from 2005 to 2012, and also estimated gene-environment interactions. In the replication phase, we used data from the Yakumo Study conducted in 2009. In the discovery phase, data of 2,263 participants from four independent study sites of the J-MICC Study were analyzed. In the replication phase, data of 573 participants from the Yakumo Study were analyzed. RESULTS: For Hcy, MTHFR locus on chr 1, NOX4 on chr 11, CHMP1A on chr 16, and DPEP1 on chr 16 reached genome-wide significance (P < 5×10-8). MTHFR also associated with FA, and FUT2 on chr 19 associated with VB12. We investigated gene-environment interactions in both studies and found significant interactions between MTHFR C677T and ever drinking, current drinking, and physical activity > 33% on Hcy (ß = 0.039, 0.038 and -0.054, P = 0.018, 0.021 and < 0.001, respectively) and the interaction of MTHFR C677T with ever drinking on FA (ß = 0.033, P = 0.048). CONCLUSIONS: The present GWAS revealed the folate metabolism-associated genetic loci and gene-environment interactions with drinking and physical activity in Japanese, suggesting the possibility of future personalized CVD prevention.

Sex-specific Relationship Between Stress Coping Strategies and All-cause Mortality: Japan Multi-Institutional Collaborative Cohort Study.

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" use 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 for "sometimes" were 0.81 (95% confidence interval [CI], 0.67-0.97) for emotional expression, 0.79 (95% CI, 0.66-0.95) for emotional support-seeking, and 0.80 (95% CI, 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). CONCLUSION: In a large Japanese sample, selected coping strategies were associated with all-cause mortality. The relationship of emotional support-seeking was different between men and women.

Population-Based Impact of Smoking, Drinking, and Genetic Factors on HDL-cholesterol Levels in J-MICC Study Participants.

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, of which 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. CONCLUSION: 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.

Trajectories of fathers' childcare involvement and child behavioral outcomes.

BACKGROUND: Father's closeness and playful behavior influence a child's emotional and cognitive development. In this study, we aimed to assess the long-term association of paternal involvement in childcare at 1-3 years of life on subsequent behavioral outcomes at 8 years of age. METHODS: Data were obtained from the 2010 cohort of the Longitudinal Survey of Newborns in the 21st century in Japan. We used group-based trajectory modeling to predict the trajectory of total childcare scores in surveys 1, 2 and 3 to determine the overall involvement of fathers in childcare during early childhood. The level of fathers' involvement in childcare was categorized as "low", "medium" and "high". Responses from the eighth survey were used to assess child behavioral outcomes using five indicators when the child was 8 years old. Crude and adjusted logistic regression analysis was conducted to estimate the odds ratio (OR) separately for each of the behavioral outcomes of the child. RESULTS: Among the 17,027 father-child dyads included in this study, two-thirds of the fathers were of the age group 30-39 years. Compared to low involvement, children of fathers with high involvement in childcare during the early childhood years were less likely to not want to go to school even after adjusting for covariates (adjusted OR, 0.46; 95% CI: 0.32-0.66). CONCLUSIONS: Children benefit from their fathers' involvement in early childcare activities. To improve a child's well-being, fathers should be encouraged by providing them with a suitable working environment with flexible arrangements and the opportunity to involve in childcare.

Associations Between Occupational Status, Support at Work, and Salivary Cortisol Levels.

OBJECTIVE: The present study investigated associations between occupation, job stress, and salivary cortisol levels after psychological tasks. METHODS: We examined 766 (273 men and 493 women) healthy employed Japanese participants aged 21 to 68 years (mean age = 46.4 years, standard deviation = 8.5) with three types of occupation: manager, teacher, and general worker. The Brief Job Stress Questionnaire was used to evaluate participants' job stress levels, including job demand, job control, support from supervisors, and support from coworkers. Salivary cortisol levels were measured at pre-session, post-stressful tasks, and post-relaxation. All samples were assayed using an enzyme-linked immunosorbent assay test. Natural log transformation was applied before statistical analyses. A multiple regression analysis and a repeated measures analysis of covariance were conducted to test associations between occupation and salivary cortisol levels, adjusting for confounding factors. Statistical analyses were conducted separately for men and women. RESULTS: Among both men and women, general workers had higher cortisol levels than managers throughout the experimental session (men 0.6 µg/dL and 0.4 µg/dL, respectively; women 0.5 µg/dL and 0.4 µg/dL, respectively). Job control was positively associated with cortisol levels measured in all sessions, after adjusting for confounding factors (standardized beta 0.15, 0.21, and 0.18 for pre-session, post-stressful-tasks, and post-relaxation, respectively, all p < 0.05). Men with low support from coworkers had higher cortisol levels than those with high support through the sessions (0.6 µg/dL and 0.4 µg/dL, respectively). CONCLUSION: Socioeconomic disparity according to occupational status was related to cortisol levels in Japanese workers. Support from coworkers may be effective for reducing cortisol secretion in men.

Study Profile of the Japan Multi-institutional Collaborative Cohort (J-MICC) Study.

BACKGROUND: The Japan Multi-institutional Collaborative Cohort (J-MICC) study was launched in 2005 to examine gene-environment interactions in lifestyle-related diseases, including cancers, among the Japanese. This report describes the study design and baseline profile of the study participants. METHODS: The participants of the J-MICC Study were individuals aged 35 to 69 years enrolled from respondents to study announcements in specified regions, inhabitants attending health checkup examinations provided by local governments, visitors at health checkup centers, and first-visit patients at a cancer hospital in Japan. At the time of the baseline survey, from 2005 to 2014, we obtained comprehensive information regarding demographics, education, alcohol consumption, smoking, sleeping, exercise, food intake frequency, medication and supplement use, personal and family disease history, psychological stress, and female reproductive history and collected peripheral blood samples. RESULTS: The baseline survey included 92,610 adults (mean age: 55.2 [standard deviation, 9.4] years, 44.1% men) from 14 study regions in 12 prefectures. The participation rate was 33.5%, with participation ranging from 19.7% to 69.8% in different study regions. The largest number of participants was in the age groups of 65-69 years for men and 60-64 years for women. There were differences in body mass index, educational attainment, alcohol consumption, smoking, and sleep duration between men and women. CONCLUSIONS: The J-MICC Study collected lifestyle and clinical data and biospecimens from over 90,000 participants. This cohort is expected to be a valuable resource for the national and international scientific community in providing evidence to support longer healthy lives.

The Relationship between Dental Findings and Tongue Pressure: A Survey of 745 Community-Dwelling Adults and Elderly Persons in Japan.

INTRODUCTION: Reduced tongue pressure is one of the causes of dysphagia. The purpose of this study was to investigate the relationship between dental findings and tongue pressure, and whether prosthetic treatment prevents reduced tongue pressure. METHODS: This was a cross-sectional study. Participants were 745 community-dwelling adults and elderly persons in the Goto Islands in Nagasaki, who underwent a health checkup for residents in 2015 and 2016. Data were collected on gender; age; grip strength; hemoglobin; Creatinine (Cr); glycated hemoglobin (HbA1c); history of stroke; smoking, drinking, exercise, and walking habits; number of teeth; wearing of removable dentures; functional units of natural teeth (n-FTUs), fixed prostheses (nif-FTUs), and removable dentures (t-FTUs); and tongue pressure. The associations between each variable and tongue pressure were examined using multiple regression analysis. Next, those with 3 or fewer n-FTUs were selected, and differences in tongue pressure were compared between those with 3 or fewer nif-FTUs and those with 4 or more nif-FTUs, using a propensity score matching method. RESULTS: Male gender, weak grip strength, low HbA1c, no drinking, and a low number of teeth were independent factors significantly associated with lower tongue pressure. Among participants with 3 or fewer n-FTUs, the 43 with 4 or more nif-FTUs showed significantly higher tongue pressure than the 43 with 3 or fewer nif-FTUs after propensity score matching, although the number of t-FTUs was not associated with tongue pressure. DISCUSSION/CONCLUSION: Tooth loss was significantly associated with lower tongue pressure. It was suggested that fixed prosthesis treatment might prevent the reduction of tongue pressure, but removable dentures did not have such an effect.

Sarcopenia is associated with insomnia in Japanese older adults: a cross-sectional study of data from the Nagasaki Islands study.

BACKGROUND: Sarcopenia is associated with increased mortality among older adults. Sleep-related problems have been studied as factors related to sarcopenia. This study was conducted to determine the relationship between sleep-related problems and sarcopenia among Japanese community-dwelling older adults using data from the Nagasaki Islands Study. METHODS: This cross-sectional study analyzed data collected from 2017 to 2018. A total of 1592 older adults (575 men, 36.1%) aged 65 years or older participated. Sarcopenia was evaluated using the skeletal muscle mass index and grasp powers based on the criteria of the Asian Working Group for Sarcopenia. Odds ratios for sarcopenia were calculated using logistic regression analysis. Furthermore, subgroup analysis was performed based on the following tertiles of age: 65-70 years, 71-78 years, and 79-98 years. RESULTS: The number of participants with sarcopenia was 238 (14.9%). The median age of participants in the sarcopenia group (80 years; interquartile range: 74-84) was significantly higher than in the non-sarcopenia group (73 years; interquartile range 69-79; P <  0.001). In the sarcopenia group, 70.9% of participants had difficulty initiating and/or maintaining sleep, sleep duration tended to be longer (P <  0.001), and 33.3% of participants' sleep duration was over 9 h. In a logistic regression analysis for sarcopenia, advancing age was the most prominent factor, and the adjusted odds ratio (95% confidence interval) of facing difficulty initiating and/or maintaining sleep was 1.60 (1.14-2.25). Despite longer sleep duration being a significant factor in the univariable analysis, it was not significant in the multivariable analysis. In the logistic regression analysis for sarcopenia among older adults aged 79-98 years, the odds ratio (95% confidence interval) among women was significantly low at 0.53 (0.33-0.83). CONCLUSIONS: Sarcopenia is associated with difficulty initiating and/or maintaining sleep among Japanese older adults. In sarcopenia control measures, sleep/wake disorders related to insomnia are required to be evaluated in detail to help inform nursing and medical policy.

Short stature-related single-nucleotide polymorphism (SNP) activates endothelial repair activity in elderly Japanese.

BACKGROUND: Hypertension and atherosclerosis are bidirectionally related, while platelet count could serve as an indicator of endothelial repair. Therefore, high platelet counts could be associated with hypertension by indicating more intense endothelial repair activity. Furthermore, short stature has been shown to constitute a risk of atherosclerosis. Since inflammation-related single-nucleotide polymorphism (SNP (rs3782886)) is reportedly associated with myocardial infarction and short stature, rs3782886 could be associated with a high platelet count and thus more intense endothelial repair activity. METHODS: We conducted a cross-sectional study of 988 elderly Japanese who participated in a general health check-up. Short stature was defined as a height of at or under the 25th percentile of the study population, and high platelet count as the highest tertiles of the platelet levels. RESULTS: High platelet counts were found to be independently and positively associated with hypertension while rs3782886 was independently associated with high platelet levels and short stature. The classical cardiovascular risk factor-adjusted odds ratio (OR) and 95% confidence interval (CI) of high platelet count for hypertension was 1.34 (1.02, 1.77). With non-minor homo of the rs3782886 as the reference group, the adjusted OR and 95% CI for high platelet count and short stature of minor home were 2.40 (1.30, 4.42) and 2.21 (1.16, 4.21), respectively. CONCLUSION: SNP (rs3782886) was shown to be associated with high platelet count and short stature. This result partly explains how a genetic factor can influence the impact of height on endothelial repair.

Human T-Cell Leukemia Virus-1 Infection Is Associated With Atherosclerosis as Measured by Carotid Intima-Media Thickness in Japanese Community-Dwelling Older People.

The association between human T-cell leukemia virus-1 (HTLV-1) and atherosclerosis remains to be determined. This case-control study aimed to investigate this association as measured by carotid intima-media thickness (CIMT). HTLV-1 infection was positively associated with CIMT, independent of atherosclerotic risks.

Sleep disorders among Yusho patients highly intoxicated with dioxin-related compounds: A 140-case series.

PURPOSE: Patients with Yusho, a condition caused by exposure to dioxins and dioxin-like compounds, have diverse mental and physical complaints. However, the relationship between dioxins and sleep disorders has not yet been examined. This cross-sectional study was designed to investigate problems associated with sleep among patients with Yusho. METHODS: A total of 140 participants (52.9% men, average age: 67.1 ±â€¯12.2 years) were examined using questionnaires and medical interviews by an expert on sleep medicine. Demographic and clinical characteristics, including blood concentrations of 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), which is the major cause of Yusho, were obtained from the results of recent surveys conducted by the Yusho Study Group. RESULTS: Moderate to severe symptoms of insomnia were present in 51.8% of the patients. The median Pittsburgh Sleep Quality Index global score (PSQI GS) was 8 (interquartile range: 5-11). The prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) was 30.7%; 24.3% of patients had severe RLS/WED (distressing symptoms with a frequency ≥ 1day per week). A higher blood concentration of 2,3,4,7,8-PeCDF (≥72.27 pg/g lipid) and severe RLS/WED were associated with higher odds of a PSQI GS ≥8, after adjusting for covariates (odds ratio [95% confidence interval]: 4.84 [1.10-21.25] and 4.15 [1.53-11.28], respectively). CONCLUSIONS: Symptoms of insomnia were frequent, and the prevalence of RLS/WED was high in patients with Yusho. In addition to the presence of RLS/WED, a higher blood concentration of 2,3,4,7,8-PeCDF was associated with lower subjective sleep quality.

Association of hemoglobin concentration with handgrip strength in relation to hepatocyte growth factor levels among elderly Japanese men aged 60-69 years: a cross-sectional study.

BACKGROUND: Hemoglobin concentration reportedly is positively associated with muscle strength, for example, handgrip strength. However, hemoglobin cannot repair muscle directly, but is beneficial only in a supportive role. Since hepatocyte growth factor (HGF) regulates muscle satellite cell production and differentiation, which is stimulated by organ injury, the supportive effect of hemoglobin should thus be stronger for participants with high HGF than for those with low HGF. However, the association between hemoglobin concentration and handgrip strength in relation to HGF levels remains unknown. METHODS: We conducted a cross-sectional study of 255 Japanese elderly men aged 60-69 years who participated in annual health check-ups in 2014-2015. The study population was categorized on the basis of a median value of HGF of 300.6 pg/mL. RESULTS: Among present study population, 128 participants showed low HGF. For participants with low HGF, hemoglobin concentration showed no significant association with handgrip strength (standardized parameter estimate (ß) = 0.03, p = 0.767), but for those with high HGF, hemoglobin concentration was significantly positively associated with handgrip strength (ß = 0.23, p = 0.014). CONCLUSIONS: A significant positive association between hemoglobin level and handgrip strength was established for elderly Japanese men aged 60-69 years with high HGF but not for participants with low HGF. Our finding indicates that HGF levels could determine the relationship of hemoglobin concentration with handgrip strength in elderly Japanese men aged 60-69 years. This result can be expected to serve as an effective tool for the clarification of the roles played by HGF and hemoglobin concentration in maintenance of muscle strength.