Correlates of engaging in sports and exercise volunteering among older adults in Japan.

This study aimed to identify factors associated with engaging in sports and exercise volunteering among older adults. We used cross-sectional data from the Japan Gerontological Evaluation Study (JAGES), a nationwide mail survey of 20,877 older adults from 60 municipalities. Multilevel mixed-effects logistic regression analysis was used to investigate the correlation between engaging in sports and exercise volunteering and 39 variables classified into five factors: (1) demographic and biological, (2) behavioral, (3) psychological, cognitive, and emotional, (4) social and cultural, and (5) environmental factors. Among the analyzed samples, 1580 (7.6%) participants volunteered a few times/year or more often. Factors that showed positive association with the volunteering were older age, a current drinking habit, excellent self-rated health, high proportion of sports group participants in a living area, low municipal population density, and rich social and cultural features (i.e., social cohesion, support, network, and participation). Meanwhile, those that had a negative association were women, low level of education, deteriorated instrumental activities of daily living, having a past or current smoking habit, poor self-rated health, and depressive symptoms. We clarified the characteristics of the population that is more likely to participate in sports and exercise volunteering as well as those of the population that is less likely to participate and requires support.

Koshu GRoup Activity, Active Play and Exercise (GRAPE) Study: A Cluster Randomised Controlled Trial Protocol of a School-Based Intervention among Japanese Children.

School-based programmes need to be effective, easy for all, easy to perform within a short duration, and inexpensive. However, no studies have reported whether voluntarily and very short-time active play programmes contribute to improved health outcomes. This study aims to describe the GRoup activity, Active Play and Exercise (GRAPE) cluster randomised controlled trial that examined whether active play interventions of very short durations contribute to increasing physical activity (PA) and bone mass among school-aged children. The trial was conducted in 2018 from January to June, and the activity comprised ≥2 children jumping together for approximately 10 s per session, at least five times a day (approximately 1 min/day). School clusters, pair-matched as per school size (total number of children) and region, were randomly allocated to either intervention or wait-list control groups. The primary outcomes comprised objectively measured changes in PA levels (moderate-to-vigorous PA) evaluated using wrist-worn activity trackers from baseline to the one-year follow-up (six-month post-intervention follow-up) and changes in bone mass evaluated using calcaneus quantitative ultrasound parameters. This study could describe the problems and challenges in school-based PA intervention studies and present findings that could make a potentially important contribution to health education and PA promotion.

Size of company of the longest-held job and mortality in older Japanese adults: A 6-year follow-up study from the Japan Gerontological Evaluation Study.

OBJECTIVES: Very few longitudinal studies have investigated the question of whether differences in company size may give rise to health inequalities. The aim of this study was to examine the relationship between company size of the longest-held job and mortality in older Japanese adults. METHODS: This study used longitudinal data from the Japan Gerontological Evaluation Study. Surveys were sent to functionally independent individuals aged 65 or older who were randomly sampled from 13 municipalities in Japan. Respondents were followed for a maximum of 6.6 years. The Cox proportional hazards model was used to calculate mortality hazard ratios (HRs) for men and for women. Analysis was carried out on 35 418 participants (197 514 person-years). RESULTS: A total of 3935 deaths occurred during the 6-year follow-up period. Among men, in Model 1 that adjusted for age, educational attainment, type of longest-held job, and municipalities, mortality HRs decreased significantly with increasing size of company (P for trend = .002). Compared to companies with 1-9 employees, the mortality HR (0.78, 95% confidence interval: 0.68-0.90) was significantly lower for companies with 10 000 or more employees. However, there were no significant differences among women (P for trend = .41). CONCLUSIONS: In men, mortality in old age may decrease with increasing size of company of the longest-held job. To reduce health inequalities in old age due to differences in size of company, studies should be conducted to determine the underlying mechanisms and moderating factors and those findings should be reflected in labor policies and occupational health systems.

Association between childhood socioeconomic position and sports group participation among Japanese older adults: A cross-sectional study from the JAGES 2010 survey.

Sports group participation may have greater effects on health outcomes than exercising alone. Unhealthy lifestyles were reported to be specifically associated with lower socioeconomic positions (SEPs), and child poverty and the bipolarization of sports participation are currently major policy concerns in children. However, it remains unclear whether childhood SEP has any long-latency effect on sports group participation among older Japanese. Data were obtained from the Japan Gerontological Evaluation Study 2010 project, which used self-report questionnaires to survey individuals aged ≥65 years without disability from 27 municipalities (n = 23,320). According to their answers, respondents were assigned to one of three SEP groups: high, middle, or low. Poisson regression with robust variance and multiple imputations was used to examine the association between childhood SEP and sports group participation. After adjusting for health-related factors, low childhood SEP was negatively associated with sports group participation in men (prevalence ratio [PR] = 0.82, 95% confidence interval [CI] = 0.74-0.91) and women (PR = 0.88, 95% CI = 0.80-0.97). The PR was greatly attenuated after adjusting for educational attainment in both men (PR = 0.92, 95% CI = 0.83-1.02) and women (PR = 0.98, 95% CI = 0.89-1.08), and the significant association disappeared. Low childhood SEP is thus associated with lower sports group participation among older Japanese, though this may be attenuated by education. These findings suggest that it may be necessary to consider childhood SEP and the importance of education to increase sports group participation at an older age.

Association of objectively measured physical activity and sedentary behavior with bone stiffness in peripubertal children.

INTRODUCTION: Physical activity (PA) is a key factor of bone mass acquisition in peripubertal children. Sedentary behavior (SB) has been shown to influence bone outcomes. This study aimed to examine the association between objectively measured PA and SB and bone stiffness in Japanese children. MATERIALS AND METHODS: Participants were fifth-grade children aged 10-11 years from Project Koshu. The stiffness index (SI) of the calcaneus was measured by quantitative ultrasound; PA and SB were evaluated by an accelerometer. Each PA parameter was divided into sex-specific tertile or stratified by recommended PA guideline [≥ 60 min/day of moderate-to-vigorous PA (MVPA)]. The SI was compared among PA and SB through analysis of covariance with Bonferroni correction. RESULTS: Of 174 children, complete data were obtained from 134 (60 boys and 74 girls). The SI in boys was higher in the highest tertile of MVPA than that in the other groups. A similar association was found in girls but was not significant. Children who met the PA guideline had higher SI than those who did not, but there was no significant difference. A negative relation was observed in girls, with the SI gradually decreasing along with increasing SB (p for trend = 0.038). This association was not observed among boys. CONCLUSION: This study suggests that MVPA is positively associated with bone stiffness in Japanese schoolchildren in boys and SB is negatively associated with that in girls. Reducing SB might be a brief modifiable factor for preventing lower peak bone mass in girls, in addition to increasing MVPA.

Sex Differences in Birth Weight and Physical Activity in Japanese Schoolchildren.

BACKGROUND: Lower birth weight (BW) is associated with increased chronic disease risk later in life. Previous studies suggest that this may be mediated principally via physical activity (PA). However, the association between BW and PA in children has not been clarified. The purpose of this study was to examine the association between BW and PA in school-aged children in Japan. METHODS: Participants were children from a prospective birth cohort study (Project Koshu) who were born from 1996 through 2002 in rural Japan. BWs were obtained from the Maternal and Child Health Handbook. Data on PA during childhood were collected using a self-reported questionnaire when participants were 9-15 years of age in July 2011. Analysis of covariance was used to evaluate exercise duration; Poisson regression analysis was used to evaluate if the recommended PA amount was met. RESULTS: Data from 657 children (boys: 54.8%, follow-up rate: 77.6%) were analyzed. Compared with the normal BW group, only girls in the low-BW group had significantly lower PA level (normal BW, 11.4 [standard error, 1.0] hours/week; low BW, 5.8 [standard error, 3.6] hours/week, P = 0.010), and were more likely to not meet the recommended PA level (prevalence ratio 1.57; 95% CI, 1.14-2.16). CONCLUSION: Low BW was associated with a lower PA level in school-aged girls but not boys. Earlier consideration of BW may be an important public health strategy to prevent physical inactivity in school-aged girls.

Correlates of Regular Participation in Sports Groups among Japanese Older Adults: JAGES Cross-Sectional Study.

BACKGROUND: Participation in a sports group is key for the prevention of incident functional disability. Little is known about the correlates of older adults' participation in sports groups, although this could assist with the development of effective health strategies. The purpose of this study was to identify the demographic and biological, psychosocial, behavioral, social and cultural, and environmental correlates of sports group participation among Japanese older adults. METHODS: Data were obtained from the Japan Gerontological Evaluation study, which was a population-based cohort of people aged ≥65 years without disability enrolled from 31 municipalities across Japan (n = 78,002). Poisson regression analysis was used to determine the associations between the factors and participation in sports groups. RESULTS: Non-regular participation in sports groups was associated with lower educational level, being employed, and working the longest in the agricultural/forestry/fishery industry among the demographic and biological factors and poor self-rated health and depression among the psychosocial factors. Of the behavioral factors, current smoking was negatively associated and current drinking was positively associated with regular participation in sports groups. Among the social and cultural factors, having emotional social support and participating in hobby clubs, senior citizen clubs, or volunteer groups were associated with a high prevalence of participation in sports groups. Perceptions of the presence of parks or sidewalks, good access to shops, and good accessibility to facilities were positively associated with participation in sports groups among the environmental factors. CONCLUSIONS: Our study suggests that the promotion of activities that could increase older adults' participation in sports groups should consider a broad range of demographic and biological, psychosocial, behavioral, social and cultural, and environmental factors. Although future longitudinal studies to elucidate the causal associations are needed, encouraging participation in community groups through social networks might be effective for participation in sports groups.

[Effects of age, period, and cohort on the trends in obesity rate and energy intake ratio from fat in Japanese adults].

OBJECTIVES: In the present study, we aimed to clarify the specific effects of age, period, and cohort on trends in obesity rate and energy intake ratio from fat in Japanese adults using a Bayesian age-period-cohort (APC) analysis and to evaluate the relationship between changes in obesity rate and energy intake ratio from fat. METHODS: We obtained data regarding obesity rate and calorie intake of fat, animal fat, carbohydrate, protein, animal protein, and total energy intake of Japanese adults from the National Nutrition Survey. The data were tabulated for five 10-year age groups (from 20-29 years to 60-69 years) and 17 annual demographic profiles (from 1995 to 2011), with regard to the energy intake ratio. These standard cohort tables were analyzed using a Bayesian APC model. RESULTS: With regard to obesity rate, the effect of age was the greatest and increased rapidly in the age group of 30-39 years for both genders. Moreover, the period effect consistently increased in men, but had very little variation in women. The cohort effect indicated a reverse of the decreasing trend in the cohorts born after 1962-1971 in men and indicated a reverse of the increasing trend in the cohorts born after 1965-1974 in women. With regard to the energy intake ratio from fat, the trends for the three effects differed from those for obesity rate for both genders. The age effect generally decreased with increasing age. Furthermore, for both genders, the period effect gradually decreased after 1998 and markedly decreased in 2001, remained constant or slightly increased until 2008, and increased thereafter. However, the cohort effect was the greatest among the three, and although a decreasing trend was observed in the cohorts born after 1976-1985 in women, the energy intake from fat increased in the younger cohorts in both genders. The overall effect on energy intake ratio from animal fat had a slope similar to that of the energy intake ratio from fat. CONCLUSION: Each effect affected obesity and energy intake ratio from fat in a different manner, suggesting that factors other than energy intake ratio from fat, such as energy expenditure, contributed to the changes in obesity rate. However, obesity risk markedly increased in the age group of 30-39 years, and younger generations had a higher energy intake ratio from fat. These results suggest that dietary guidelines, particularly the optimal intake of animal products, is needed for younger generations to prevent the development of obesity in adulthood.

High-intensity exercise causes greater irisin response compared with low-intensity exercise under similar energy consumption.

Irisin is mainly released from skeletal muscle (myocytes) and promotes thermogenesis by browning of the white adipose tissue. Although exercise has been shown to increase irisin concentration in blood and myocytes via up-regulation peroxisome proliferator receptor γ coactivator-1α (PGC-1α) expression, the influence of exercise intensity on irisin secretion remains unclear. Therefore, we determined circulating irisin responses following a single bout of running at different intensities. Six sedentary males underwent treadmill running under two different conditions: a low-intensity (40% of VO2max) exercise trial (LIE) or a high-intensity (80% of VO2max) exercise trial (HIE). The exercises in LIE and HIE were lasted for 20 and 40 min, respectively. All subjects underwent the two trials on separate days, and a randomized cross-over design was used. Blood samples were collected before (Pre) and immediately after exercise, at 3, 6, and 19 h after exercise. Energy consumption during exercise did not significantly differ between the two trials. HIE significantly increased blood lactate and serum lactate dehydrogenase levels (P < 0.05). Compared with pre-exercise levels, the irisin concentrations were elevated at 6 h (18% increase) and 19 h (23% increase) after HIE, but significantly decreased after LIE. The relative irisin concentrations (compared with pre-exercise levels) were significantly greater in HIE than in LIE immediately after exercise, and at 6 and 19 h after exercise (P < 0.05). These findings suggest that irisin secretion after acute running exercise is affected by exercise intensity, independent of energy consumption.

An association between the serotonin transporter gene promoter polymorphism and smoking cessation among Japanese males.

The objective of this study was to replicate the associations between the serotonin transporter genotypes and smoking cessation and between these genotypes and long-term smoking cessation success (for 2 years or more). Two case-control designs were used in this study. The first case-control design consisted of 47 ex-smokers (cases) and 94 smokers (controls). The second case-control design consisted of the 12 ex-smokers who had succeeded in long-term smoking cessation (cases) and the 24 smokers (controls). In the first design, there was no significant difference in allele frequency and genotype distribution between cases and controls. In the second design, the S/S genotype frequency was higher in cases than in controls, but the difference did not reach slightly statistical significance. The present study suggests that individuals with the S/S genotype are more inclined to achieve long-term smoking cessation than others.

Effect of molecular hydrogen saturated alkaline electrolyzed water on disuse muscle atrophy in gastrocnemius muscle.

The objectives of this paper were to determine the level of oxidative stress in atrophied gastrocnemius, and to verify the effect of molecular hydrogen (H2) saturated alkaline electrolyzed water (HSW) on gastrocnemius atrophy by modifying the redox status, indicated by 8-hydroxy-2'-deoxyguanosine (8-OHdG), malondialdehyde (MDA), and superoxide dismutase (SOD)-like activity. Female Wistar rats were divided into four groups: (1) the control (CONT); (2) the Hindlimb unloading (HU, for 3 weeks) given purified normal water (HU-NW); (3) the HU given alkaline electrolyzed reduced water (HU-AEW); and (4) the HU given HSW (HU-HSW). We showed that 8-OHdG, but not MDA, significantly increased by 149% and 145% in HU-NW and HU-AEW, respectively, when compared with CONT. In contrast, there was a trend toward suppression in 8-OHdG levels (increased by 95% compared with CONT) by treatment of HSW, though this effect was not prominent. Additionally, SOD-like activity significantly increased in both HU-NW (184%) and HU-AEW (199%) when compared with CONT. This result suggests the elevation of O2-· in the atrophied gastrocnemius. However, upregulation of SOD-like activity in the HU-HSW was increased by only 169% compared with CONT, though this difference is too small to detect statistical significance. HU led to 13% and 15% reduction of gastrocnemius wet weights in HU-NW and HU-AEW, respectively, compared with CONT. And the reduction of gastrocnemius wet weights in HU-HSW was attenuated by 7% compared with CONT. The gastrocnemius wet weights in the HU-HSW group were significantly greater than those in the HU-AEW, but not statistically significant with HU-NW. These results indicate that HU causes an increase in oxidative stress, but, in this experimental protocol, continuous consumption of HSW during HU does not demonstrate successful attenuation of oxidative stress and HU-mediated gastrocnemius atrophy.

The Trp64Arg polymorphism of the beta3-adrenergic receptor gene is associated with weight changes in obese Japanese men: a 4-year follow-up study.

The aim of this study was to investigate whether the Trp64Arg polymorphism of the beta(3)-adrenergic receptor gene (ADRB3) is associated with weight changes in obese Japanese men at 4-year follow-up. The participants were 145 obese Japanese men [age: 35.8+/-5.3 y; body mass index (BMI): 27.5+/-3.3 kg/m(2)]. The participants were divided into two groups according to the Trp64Arg genotype: (1) with the Arg64 allele of the ADRB3 (Trp64Arg and Arg64Arg genotypes, n=50); (2) without the Arg64 allele of the ADRB3 (Trp64Trp genotype, n=95). The ADRB3 genotyping was performed by denaturing high performance liquid chromatography (DHPLC). Body weight, BMI, and blood pressure were determined at baseline and at 4 years. After 4 years, the participants with the Arg allele of the ADRB3 significantly increased their body weight (2.1+/-4.7 kg, p=0.002) and BMI (0.64+/-1.6 kg/m(2), p=0.006) whereas the participants without the Arg allele of the ADRB3 did not significantly change in these parameters (body weight: -0.36+/-4.2 kg, p=0.41; BMI: -0.24+/-1.5 kg/m(2), p=0.12). The results in this study showed that the Arg allele of the ADRB3 is associated with long-term changes in body weight in obese individuals. This polymorphism may become an indicator in personalized weight loss programs in obese men.

Effects of glutathione depletion on hypoxia-induced erythropoietin production in rats.

In vitro studies have indicated that reactive oxygen species modifying cellular redox status are involved in hypoxia-induced erythropoietin (EPO) production. However, the effects of redox balance on hypoxia-induced EPO production in vivo are still not fully understood. To investigate the effect of the change in cellular redox status on EPO generation, we determined whether glutathione (GSH) depletion has a significant influence on hypoxia-induced EPO production in rats. For the inhibition of GSH synthesis, DL-buthionine-[S,R]-sulfoximine (BSO) was employed by intraperitoneal injection. Twenty male rats were assigned to one of four experimental groups: (1) normoxic placebo, (2) normoxic BSO, (3) hypoxic placebo, and (4) hypoxic BSO. Hypoxic groups were exposed to a simulated normobaric hypoxic condition (4,500 m above sea level) for 12 hours. BSO treatment resulted in a significant depletion of total GSH levels in kidney and plasma in both conditions. However, the hypoxia-induced elevation in serum EPO concentration was not completely affected by the inhibition of GSH synthesis. These data demonstrate that GSH depletion in the kidney is not involved in the increase in serum EPO concentration in response to systemic hypoxia. It is also conceivable that the cellular redox changes could not function as a primary regulator of hypoxia-induced renal erythropoietin formation in vivo.

The apolipoprotein E gene polymorphism is associated with open angle glaucoma in the Japanese population.

PURPOSE: To assess whether genetic polymorphisms of the apolipoprotein E (APOE) gene are associated with open angle glaucoma (OAG) in the Japanese population. METHODS: Genomic DNA was examined in a cohort of 310 Japanese patients with OAG and 179 control subjects. The average age was 63.5+/-14.4 years (mean+/-SD) for the OAG patients and 65.5+/-11.6 years for the control subjects. The presence or absence of OAG in patients and controls was based on clinical examination and/or ophthalmic records. The APOE allele frequency (epsilon2, epsilon3, and epsilon4 alleles) was studied by restriction fragment length polymorphism, and compared between OAG patients and control subjects. The association between the intraocular pressure (IOP) and the APOE alleles was also evaluated. RESULTS: There was a significant difference in the APOE genotype frequencies between these groups (p=0.0006 chi2 test). The frequencies of the epsilon2 and epsilon4 alleles were significantly lower in the OAG patients (epsilon2: 2.6%; epsilon4: 6.0%) compared to the control subjects (epsilon2: 5.0%, p=0.048; epsilon4: 10.6%, p=0.012; Fisher's exact test). The frequency of the epsilon3 allele was significantly higher in the OAG patients (91.4%) compared to the control subjects (84.4%, p=0.0010; Fisher's exact test). Adjusted for age, gender, and IOP, an appropriate three fold reduction in OAG risk (odds ratio [OR] 0.29, 95% confidence interval [CI] 0.10 to 0.80; p=0.018) was found with the epsilon2 allele and a two fold increased risk of OAG (OR 1.97, 95% CI 1.06 to 3.67; p=0.033) was found with the epsilon3 allele. The maximum IOP (18.3+/-6.0 mm Hg) in patients with the epsilon4 allele was significantly lower than that (21.3+/-9.1 mm Hg) in patients without the epsilon4 allele (p=0.006, Student's t-test). CONCLUSIONS: The APOE gene polymorphism is associated with OAG in the Japanese population. Further studies in the other ethnic populations should be performed to elucidate the relationship between APOE and OAG.