Kokoro Shirai

Social Participation and the Prevention of Functional Disability in Older Japanese: The JAGES Cohort Study

Background We examined the relationship between incident functional disability and social participation from the perspective of number of types of organizations participated in and type of social participation in a prospective cohort study. Method The study was based on the Aichi Gerontological Evaluation Study (AGES) Cohort Study data. We followed 13,310 individuals aged 65 years or older for 4 years. Analysis was carried out on 12,951 subjects, excluding 359 people whose information on age or sex was missing. Social participation was categorized into 8 types. Results Compared to those that did not participate in any organizations, the hazard ratio (HR) was 0.83 (95% CI: 0.73–0.95) for participation in one, 0.72 (0.61–0.85) for participation in two, and 0.57 (0.46–0.70) for participation in three or more different types of organizations. In multivariable adjusted models, participation in the following types of organization was protective for incident disability: local community organizations (HR = 0.85, 95% CI: 0.76–0.96), hobby organizations (HR = 0.75, 95% CI: 0.64–0.87), and sports organizations (HR = 0.64, 95% CI: 0.54–0.81). Conclusion Social participation may decrease the risk of incident functional disability in older people in Japan. This effect may be strengthened by participation in a variety of different types of organizations. Participating in a local community, hobby, or sports group or organization may be especially effective for decreasing the risk of disability.

Does walkable mean sociable? Neighborhood determinants of social capital among older adults in Japan.

Why are some communities more cohesive than others? The answer to the puzzle has two parts: (a) due to variations in the attributes of residents, and/or (b) due to variations in the attributes of places. However, few studies have sought to examine the community-level determinants of social capital. In the present study, we examined the associations between social capital and different area characteristics: (1) neighborhood walkability, (2) date of community settlement, and (3) degree of urbanization. We based our analysis on 9414 respondents from the Aichi Gerontological Evaluation Study (AGES), conducted in 2003. No significant positive association was found between the walkability score and any of the social capital indices. In contrast, community age and degree of urbanization were associated with many of the social capital indicators, even after controlling for characteristics of the residents. Community social capital thus appears to be more consistently linked to the broader historical and geographic contexts of neighborhoods, rather than to the proximal built environment (as measured by walkability).

Perceived Level of Life Enjoyment and Risks of Cardiovascular Disease Incidence and Mortality: The Japan Public Health Center–Based Study

Background— Perceived level of life enjoyment, a positive psychological condition that reflects the ability to engage pleasurably with the environment, may relate to risks of cardiovascular disease. This prospective cohort study attempted to examine the effects of perceived level of life enjoyment on cardiovascular disease incidence and mortality among Japanese community residents. Methods and Results— Subjects were 88 175 Japanese men and women 40 to 69 years of age who were free of cardiovascular disease at baseline and followed up for a median of 12.0 years and were included in the Japan Public Health Center–Based (JPHC) Study Cohort. Data about psychological conditions and other confounding variables were obtained through self-administered questionnaires. Information on incidence and mortality for cardiovascular disease was collected through registered hospitals and public health centers. The multivariable hazard ratios of cardiovascular disease incidence for men in the high versus low perceived levels of life enjoyment group were 1.22 (95% confidence interval, 1.01 to 1.47) for stroke and 1.23 (95% confidence interval, 1.05 to 1.44) for total cardiovascular disease. As for mortality, Japanese men with low perceived level of life enjoyment showed increased risk: hazard ratios of 1.75 (95% confidence interval, 1.28 to 2.38) for stroke, 1.91 (95% confidence interval, 1.30 to 2.81) for coronary heart disease and 1.61 (95% confidence interval, 1.32 to 1.96) for total cardiovascular disease. For women, however, the perceived level of life enjoyment was not associated with risks of cardiovascular disease incidence or mortality. Conclusion— A lower perceived level of life enjoyment was found to be associated with higher risks of cardiovascular disease incidence and mortality among middle-aged men, suggesting a protective role of positive psychological conditions on cardiovascular disease.

Assessing the association between all-cause mortality and multiple aspects of individual social capital among the older Japanese

BackgroundFew prospective cohort studies have assessed the association between social capital and mortality. The studies were conducted only in Western countries and did not use the same social capital indicators. The present prospective cohort study aimed to examine the relationships between various forms of individual social capital and all-cause mortality in Japan.MethodsSelf-administered questionnaires were mailed to subjects in the Aichi Gerontological Evaluation Study (AGES) Project in 2003. Mortality data from 2003 to 2008 were analyzed for 14,668 respondents. Both cognitive and structural components of individual social capital were collected: 8 for cognitive social capital (trust, 3; social support, 3; reciprocity, 2) and 9 for structural social capital (social network). Cox proportional hazard models stratified by sex with multiple imputation were used. Age, body mass index, self-rated health, current illness, smoking history, alcohol consumption, exercise, equivalent income and education were used as covariates.ResultsDuring 27,571 person-years of follow-up for men and 29,561 person-years of follow-up for women, 790 deaths in men and 424 in women were observed. In the univariate analyses for men, lower social capital was significantly related to higher mortality in one general trust variable, all generalised reciprocity variables and four social network variables. For women, lower social capital was significantly related to higher mortality in all generalised reciprocity and four social network variables. After adjusting for covariates, lower friendship network was significantly associated with higher all-cause mortality among men (meet friends rarely; HR = 1.30, 95%CI = 1.10-1.53) and women (having no friends; HR = 1.81, 95%CI = 1.02-3.23). Among women, lower general trust was significantly related to lower mortality (most people cannot be trusted; HR = 0.65, 95%CI = 0.45-0.96).ConclusionsFriendship network was a good predictor for all-cause mortality among older Japanese. In contrast, mistrust was associated with lower mortality among women. Studies with social capital indices considering different culture backgrounds are needed.

Sex/Gender and Socioeconomic Differences in the Predictive Ability of Self-Rated Health for Mortality

Background Studies have reported that the predictive ability of self-rated health (SRH) for mortality varies by sex/gender and socioeconomic group. The purpose of this study is to evaluate this relationship in Japan and explore the potential reasons for differences between the groups. Methodology/Principal Findings The analyses in the study were based on the Aichi Gerontological Evaluation Studys (AGES) 2003 Cohort Study in Chita Peninsula, Japan, which followed the four-year survival status of 14,668 community-dwelling people who were at least 65 years old at the start of the study. We first examined sex/gender and education-level differences in association with fair/poor SRH. We then estimated the sex/gender- and education-specific hazard ratios (HRs) of mortality associated with lower SRH using Cox models. Control variables, including health behaviors (smoking and drinking), symptoms of depression, and chronic co-morbid conditions, were added to sequential regression models. The results showed men and women reported a similar prevalence of lower SRH. However, lower SRH was a stronger predictor of mortality in men (HR = 2.44 [95% confidence interval (CI): 2.14–2.80]) than in women (HR = 1.88 [95% CI: 1.44–2.47]; p for sex/gender interaction = 0.018). The sex/gender difference in the predictive ability of SRH was progressively attenuated with the additional introduction of other co-morbid conditions. The predictive ability among individuals with high school education (HR = 2.39 [95% CI: 1.74–3.30]) was similar to that among individuals with less than a high school education (HR = 2.14 [95% CI: 1.83–2.50]; p for education interaction = 0.549). Conclusions The sex/gender difference in the predictive ability of SRH for mortality among this elderly Japanese population may be explained by male/female differences in what goes into an individuals assessment of their SRH, with males apparently weighting depressive symptoms more than females.

White blood cell count as a risk factor for hypertension; a study of Japanese male office workers.

Objective To investigate the association of white blood cell (WBC) count with risk of hypertension. Design Cross-sectional and longitudinal studies. Setting A work site in Japan. Participants A total of 3776 Japanese male office workers aged 23–49 years were enrolled in this study; 2900 hypertension-free [systolic blood pressure (SBP) < 140 mmHg, diastolic blood pressure (DBP) < 90 mmHg, no medication for hypertension, and no past history of hypertension] men were followed up over a 4-year period. Main outcome measures Blood pressure levels and the incidence of hypertension (SBP ⩾ 140 mmHg and/or DBP ⩾ 90 mmHg or medication for hypertension) according to WBC count at study entry. Results After controlling for potential predictors of hypertension, SBP and DBP levels increased in a dose-dependent manner among both never-smokers and ex-smokers as WBC count increased. Among current smokers, only SBP level increased progressively with WBC count level. The multivariate-adjusted relative risk for development of hypertension compared with the first WBC count quintile was 1.29, 1.21, 1.67, and 1.92 among never-smokers (P for trend = 0.002): and 1.34, 1.46, 1.84, and 1.97 among ex-smokers (P for trend = 0.030) with the second, third, fourth, and fifth quintiles, respectively. Among current smokers, the respective multivariate-adjusted relative risks for hypertension relative to the first WBC count quintile were 0.91, 0.97, 1.08, and 0.84 (P for trend = 0.999). Conclusions WBC count is an important risk factor for hypertension, and the increased risk for hypertension associated with WBC count is more pronounced in non-smokers.

Associations of Childhood Socioeconomic Status and Adulthood Height With Functional Limitations Among Japanese Older People: Results From the JAGES 2010 Project

BACKGROUND We examined the associations between childhood socioeconomic status and adulthood height with functional limitations in old age. METHODS Data were obtained from the baseline survey of the Japan Gerontological Evaluation Study 2010, a population-based cohort of people aged ≥65 years enrolled from 27 municipalities across Japan (N = 15,499). People aged 65-69, 70-74, 75-79, and ≥80 years experienced the end of World War II when they were aged 0-4, 5-9, 10-14, and ≥15 years, respectively. Subjective socioeconomic status during childhood and current height were obtained by self-report through questionnaire in 2010. Higher-level functional capacity was assessed using a validated questionnaire scale. Poisson regression with robust variance estimator was employed to determine the association between childhood subjective socioeconomic status, height, and functional limitations. RESULTS Lower childhood subjective socioeconomic status was consistently associated with higher prevalence rate ratio of limitations in higher-level functional capacity, regardless of age cohort. Height was associated with functional limitation only among the group aged 70-74 years: taller (≥170cm for men and ≥160cm for women) people were 16% less likely to report functional limitation in comparison with shorter (<155 cm for men and <145 cm for women) individuals in the fully adjusted model (prevalence rate ratio: 0.84, 95% confidence interval: 0.74-0.96). CONCLUSIONS Low childhood subjective socioeconomic status had a robust association with functional limitation regardless of age cohort. In addition, those who lived through World War II before they reached puberty and attained shorter height were more likely to report functional limitations in old age.

Laughter is the Best Medicine? A Cross-Sectional Study of Cardiovascular Disease Among Older Japanese Adults

Background We sought to evaluate the associations between frequency of daily laughter with heart disease and stroke among community-dwelling older Japanese women and men. Methods We analyzed cross-sectional data in 20 934 individuals (10 206 men and 10 728 women) aged 65 years or older, who participated in the Japan Gerontological Evaluation Study in 2013. In the mail-in survey, participants provided information on daily frequency of laughter, as well as body mass index, demographic and lifestyle factors, and diagnoses of cardiovascular disease, hyperlipidemia, hypertension, and depression. Results Even after adjustment for hyperlipidemia, hypertension, depression, body mass index, and other risk factors, the prevalence of heart diseases among those who never or almost never laughed was 1.21 (95% CI, −1.03–1.41) times higher than those who reported laughing every day. The adjusted prevalence ratio for stroke was 1.60 (95% CI, 1.24–2.06). Conclusions Daily frequency of laughter is associated with lower prevalence of cardiovascular diseases. The association could not be explained by confounding factors, such as depressive symptoms.

Laughter and Subjective Health Among Community-Dwelling Older People in Japan: Cross-Sectional Analysis of the Japan Gerontological Evaluation Study Cohort Data.

Abstract The aim of this study was to evaluate the association of laughter with subjective health independent of socioeconomic status and social participation among older people in Japan. We used the data of 26,368 individuals (men, 12,174; women, 14,194) 65 years or older who participated in the Japan Gerontological Evaluation Study (JAGES) in 2013. Participants provided information on laughter and self-rated health, depression, socioeconomic, and psychosocial factors. We evaluated laughter from three perspectives: frequency, opportunities, and interpersonal interactions. Even after adjustment for depression, sociodemographic factors, and social participation, the prevalence ratio for poor subjective health among women who never or almost never laugh was 1.78 (95% confidence interval, 1.48–2.15) compared with those who reported laughing every day. Similar associations were observed among men. Laughter may be an important factor for the promotion of general and mental health of older adults. The mechanisms linking laughter and health warrant further study.

Association between social participation and hypertension among older people in Japan: the JAGES Study

Hypertension is an important risk factor for cardiovascular disease, the leading cause of mortality in the world. Although previous studies have focused on individual-level behavioral risk factors associated with hypertension, there has been little research on how interacting with others, that is social participation, affects hypertension. To address this research gap, this study examined the association between social participation and hypertension in Japan, a country with a high prevalence of hypertension possibly linked to rapid population aging. Data were used from 4582 participants aged more than 65 years who participated in the Japan Gerontological Evaluation Survey (JAGES) with blood pressure data collected during a health check-up. The frequency of participation in vertical organizations (characterized by hierarchical relationships) and horizontal organizations (characterized by non-hierarchical, egalitarian relationships) was measured by a questionnaire. In a Poisson regression analysis, participation in vertical organizations was not associated with hypertension, whereas participation in horizontal organizations at least once a month was inversely associated with hypertension (prevalence ratio: 0.941). This association remained significant after adjusting for social support variables, although further adjustment for health behaviors attenuated the association. As the frequency of going out and average time spent walking were both associated with hypertension, physical activity may be a possible pathway that connects social participation and hypertension. The results of this study suggest that expanding social participation programs, especially those involving horizontal organizations, may be one way to promote better health among older people in Japan.