Aki Yazawa

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.

Impact of Lifestyle Changes on Stress in a Modernizing Rural Population in Hainan Island, China

Little is known about inter‐individual variation in psychological stress in modernizing rural populations in developing countries. The objective of this study was to investigate the association between Epstein‐Barr virus (EBV) antibody titer, a biomarker of psychological stress, and lifestyle parameters in rural communities in Hainan Island, China.

Epstein-Barr virus antibody titer and its association with the domain scores from the World Health Organization's Quality of Life questionnaire: Findings from Rural Hainan Province, China.

Epstein‐Barr virus (EBV) antibody titer has recently been used as a biomarker of psychological stress. This is the first study to investigate the association between EBV antibody titer and perceived quality of life (QOL) in Hainan Island, China.

Neighborhood Characteristics and Cardiovascular Risk among Older People in Japan : Findings from the JAGES Project

Previous studies have found an association between neighborhood characteristics (i.e., aspects of the physical and social environment) and the incidence of cardiovascular disease (CVD) and elevated CVD risk. This study investigated the relationship between neighborhood characteristics and CVD risk among older people in Japan where research on this association is scarce. Data came from the Japan Gerontological Evaluation Study project; questionnaire data collected from 3,810 people aged 65 years or older living in 20 primary school districts in Aichi prefecture, Japan, was linked to a computed composite CVD risk score based on biomarker data (i.e., hemoglobin A1c, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and estimated glomerular filtration rate). A sex-stratified multilevel linear regression analysis revealed that for male participants, living in neighborhoods with a higher perceived occurrence of traffic accidents and reduced personal safety was associated with an elevated CVD risk (coefficient = 1.08 per interquartile range increase, 95% confidence interval [CI] = 0.30 to 1.86) whereas males living in neighborhoods with a higher perceived proximity of exercise facilities had a lower risk (coefficient = −1.00, 95% CI = −1.78 to −0.21). For females, there was no statistically significant association between neighborhood characteristics and CVD risk. This study suggests that aspects of the neighborhood environment might be important for CVD morbidity and mortality in Japan, particularly among men.

The association between economic development, lifestyle differentiation, and C-reactive protein concentration within rural communities in Hainan Island, China

Earlier fieldwork in rural areas of Hainan Island, China, demonstrated that during the course of economic development increasing differences had emerged in lifestyles within communities. It is possible that these variations might have stratified residents into subpopulations with different health attributes. This study examined the association between C‐reactive protein (CRP) concentration, a biomarker of future cardiovascular events, and personal lifestyle parameters and the degree of community‐level economic development among rural communities.

The Effects of Season of Birth on the Inflammatory Response to Psychological Stress in Hainan Island, China

Season of birth (SOB) has been investigated as one of the environmental factors that might epigenetically determine the physiology of individuals. This study investigated the role of SOB in the association between Quality of Life (QOL), a proxy of psychological stress status, and C-reactive protein (CRP) concentration (i.e., inflammatory status) among 1,085 adults (aged 20–57 years old) in Hainan Island, China. High sensitivity CRP concentration was measured in dried blood spot samples, while the abbreviated version of the World Health Organization’s QOL questionnaire was used to gather information on six QOL domains. Analysis stratified by three historically distinct age groups revealed a significant association between CRP concentration, SOB, QOL and an interaction between SOB and QOL among the youngest and oldest groups. In the oldest group, those born in the dry season had a higher CRP concentration with worse QOL whereas in the youngest group, there was a higher CRP concentration with better QOL. Annual per capita rice production, a proxy of population nutritional status in the year of birth, was found to predict CRP concentration only among the second oldest group. These findings suggest that the early environment might affect the immune response to psychological stress in adulthood and that its effect may differ by the time period in which people were born.

Epstein-Barr virus antibody titer as a stress biomarker and its association with social capital in rural Fujian communities, China

There has been little research on the association between social capital and psychological stress measured by a biomarker, particularly in developing countries. Our objective was to investigate the association between Epstein‐Barr virus (EBV) antibody titer, an indicator of cellular immune function previously shown to be associated with psychological stress, and social capital among rural community dwellers in Fujian Province, China.

Adverse childhood experiences, exposure to a natural disaster and posttraumatic stress disorder among survivors of the 2011 Great East Japan earthquake and tsunami

AIMS To investigate whether adverse childhood experiences (ACEs) modify the impact of exposure to a natural disaster (the 2011 Great East Japan earthquake and tsunami) on the occurrence of posttraumatic stress disorder (PTSD) among older people. METHODS Data were collected as part of the Japan Gerontological Evaluation Study (JAGES), which is an on-going epidemiological survey investigating social determinants of health among older people across Japan. Information on PTSD symptoms based on the Screening Questionnaire for Disaster Mental Health, traumatic exposure to the earthquake (i.e., house damage and loss of relatives/friends during the earthquake/tsunami) and ACEs was obtained from 580 participants aged 65 or older living in Iwanuma City, Miyagi Prefecture, which suffered severe damage as a result of the earthquake and the subsequent tsunami in March 2011. Associations were examined using Poisson regression analysis with a robust variance estimator after adjusting for covariates. RESULTS The prevalence of PTSD was 9.7% in this population; compared to those with no traumatic experience, the prevalence of PTSD was approximately two times higher among those who experienced the loss of close friends/relatives (PR = 1.84, 95% CI = 1.11-3.03, p = 0.018), or whose house was damaged (PR = 2.15, 95% CI = 1.07-4.34, p = 0.032). ACE was not significantly associated with PTSD. Stratified analyses by the presence of ACE showed that damage due to the earthquake/tsunami was associated with PTSD only among those without ACEs; more specifically, among non-ACE respondents the PR of PTSD associated with house damage was 6.67 (95% CI = 1.66-26.80), while for the loss of a relative or a close friend it was 3.56 (95% CI = 1.18-10.75). In contrast, no statistically significant associations were observed among those with ACEs. CONCLUSION Following the Great East Japan earthquake/tsunami in 2011 a higher risk of developing PTSD symptoms was observed in 2013 especially among older individuals without ACEs. This suggests that ACEs might affect how individuals respond to subsequent traumatic events later in life.

Month of birth is associated with mortality among older people in Japan: Findings from the JAGES cohort

ABSTRACT Month of birth (MOB) has been linked to a variety of health conditions in adulthood. This study examined the association between MOB and mortality among the healthy elderly in Japan, where a practice of traditional age reckoning was employed up until the late 1940s. The results showed male participants born in December were more likely to die earlier while those born in January had lower mortality. It is possible that social factors in early life, such as the time period when a birth is officially registered, may have implications for health that stretch across the life course.