Masashige Saito

Japanese cases of familial hemiplegic migraine with cerebellar ataxia carrying a T666M mutation in the CACNA1A gene

Familial hemiplegic migraine (FHM) is an autosomal dominantly inherited disorder characterised by migraine attacks preceded by transient hemiparesis. In 1993, Joutel et al mapped the locus for FHM to chromosome 19p13 by linkage analysis,1 and the causative gene was subsequently identified as the CACNA1A gene, encoding a P/Q-type calcium channel α1A subunit. Cases involving the CACNA1A gene have been found in approximately 50% of FHM cases, and linkage to chromosome 1 has been shown in some of the other families. FHM with progressive cerebellar ataxia (FHM/PCA) has been described only in cases carrying CACNA1A mutations. Other clinical phenotypes associated with ataxia may also be caused by mutations in the CACNA1A gene, which include episodic ataxia type 2 (EA-2) and spinocerebellar ataxia type 6 (SCA6). EA-2 is characterised by recurrent episodes of attacks of cerebellar ataxia accompanied by interictal nystagmus. In SCA6, expansion of a CAG trinucleotide repeat coding for a polyglutamine stretch at the carboxyl terminus of the CACNA1A has been identified as the causative mutation. These data suggest that mutations in the CACNA1A …

Relative deprivation, poverty, and subjective health: JAGES cross-sectional study.

To evaluate the association between relative deprivation (lacking daily necessities) and subjective health in older Japanese adults, we performed a cross-sectional analysis using data from the Japan Gerontological Evaluation Study (JAGES). The data were obtained from functionally independent residents aged ≥65 years from 24 municipalities in Japan (n = 24,742). Thirteen items in three dimensions were used to evaluate relative deprivation of material conditions. Approximately 28% of older Japanese people indicated that they lacked some daily necessities (non-monetary poverty). A two-level Poisson regression analysis revealed that relative deprivation was associated with poor self-rated health (PR = 1.3–1.5) and depressive symptoms (PR = 1.5–1.8) in both men and women, and these relationships were stronger than those observed in people living in relative poverty (monetary poverty). The interaction effect between relative deprivation and relative poverty was not associated with poor health. As a dimension of the social determinants of health, poverty should be evaluated from a multidimensional approach, capturing not only monetary conditions but also material-based, non-monetary conditions.

Gender differences on the impacts of social exclusion on mortality among older Japanese: AGES cohort study

To evaluate the gender-specific impact of social exclusion on the mortality of older Japanese adults, we performed a prospective data analysis using the data of the Aichi Gerontological Evaluation Study (AGES). In AGES, we surveyed functionally independent residents aged 65 years or older who lived in six municipalities in Aichi prefecture, Japan. We gathered baseline information from 13,310 respondents in 2003. Information on mortality was obtained from municipal databases of the public long-term care insurance system. All participants were followed for up to 4 years. We evaluated social exclusion in terms of the combination of social isolation, social inactivity, and relative poverty. Coxs proportional hazard model revealed that socially excluded older people were at significantly increased risk (9-34%) for premature mortality. Those with simultaneously relative poverty and social isolation and/or social inactivity were 1.29 times more likely to die prematurely than those who were not socially excluded. Women showed stronger overall impact of social exclusion on mortality, whereas relative poverty was significantly associated with mortality risks for men. If these associations are truly causal, social exclusion is attributable to 9000-44,000 premature deaths (1-5%) annually for the older Japanese population. Health and social policies to mitigate the issue of social exclusion among older adults may require gender-specific approaches.

Combined effects of eating alone and living alone on unhealthy dietary behaviors, obesity and underweight in older Japanese adults: Results of the JAGES.

We examined whether eating alone is associated with dietary behaviors and body weight status, and assessed the modifying effects of cohabitation status in older Japanese people. Data from the 2010 Japan Gerontological Evaluation Study, with a self-reported questionnaire for 38,690 men and 43,674 women aged ≥65 years, were used. Eating status was classified as eating with others, sometimes eating alone, or exclusively eating alone. We calculated adjusted prevalence ratios (APRs) of unhealthy dietary behaviors, obesity, and underweight, adjusting for age, education, income, disease, and dental status using Poisson regression. Overall, 16% of men and 28% of women sometimes or exclusively ate alone. Among those who exclusively ate alone, 56% of men and 68% of women lived alone. Men who exclusively ate alone were 3.74 times more likely to skip meals than men who ate with others. Among men who exclusively ate alone, those who lived alone had a higher APR than men who lived with others. Compared with subjects who ate and lived with others, the APRs of being obese (BMI ≥ 30.0 kg/m(2)) among men who exclusively ate alone were 1.34 (1.01-1.78) in those who lived alone and 1.17 (0.84-1.64) in those who lived with others. These combined effects of eating and living alone were weaker in women, with a potential increase in the APRs among those who ate alone despite living with others. Men who exclusively ate alone were more likely to be underweight (BMI < 18.5 kg/m(2)) than men who ate with others in both cohabitation statuses. Eating alone and living alone may be jointly associated with higher prevalence of obesity, underweight and unhealthy eating behaviors in men.

Relative deprivation in income and mortality by leading causes among older Japanese men and women: AGES cohort study

Background Relative deprivation of income is hypothesised to generate frustration and stress through upward social comparison with ones peers. If psychosocial stress is the mechanism, relative deprivation should be more strongly associated with specific health outcomes, such as cardiovascular disease (compared with other health outcomes, eg, non-tobacco-related cancer). Methods We evaluated the association between relative income deprivation and mortality by leading causes, using a cohort of 21 031 community-dwelling adults aged 65 years or older. A baseline mail-in survey was conducted in 2003. Information on cause-specific mortality was obtained from death certificates. Our relative deprivation measure was the Yitzhaki Index, derived from the aggregate income shortfall for each person, relative to individuals with higher incomes in that persons reference group. Reference groups were defined according to gender, age group and same municipality of residence. Results We identified 1682 deaths during the 4.5 years of follow-up. A Cox regression demonstrated that, after controlling for demographic, health and socioeconomic factors including income, the HR for death from cardiovascular diseases per SD increase in relative deprivation was 1.50 (95% CI 1.09 to 2.08) in men, whereas HRs for mortality by cancer and other diseases were close to the null value. Additional adjustment for depressive symptoms and health behaviours (eg, smoking and preventive care utilisation) attenuated the excess risks for mortality from cardiovascular disease by 9%. Relative deprivation was not associated with mortality for women. Conclusions The results partially support our hypothesised mechanism: relative deprivation increases health risks via psychosocial stress among men.

Development of an instrument for community-level health related social capital among Japanese older people: The JAGES Project

Background We developed and validated an instrument to measure community-level social capital based on data derived from older community dwellers in Japan. Methods We used cross-sectional data from the Japan Gerontological Evaluation Study, a nationwide survey involving 123,760 functionally independent older people nested within 702 communities (i.e., school districts). We conducted exploratory and confirmatory factor analyses on survey items to determine the items in a multi-dimensional scale to measure community social capital. Internal consistency was checked with Cronbachs alpha. Convergent construct validity was assessed via correlating the scale with health outcomes. Results From 53 candidate variables, 11 community-level variables were extracted: participation in volunteer groups, sports groups, hobby activities, study or cultural groups, and activities for teaching specific skills; trust, norms of reciprocity, and attachment to ones community; received emotional support; provided emotional support; and received instrumental support. Using factor analysis, these variables were determined to belong to three sub-scales: civic participation (eigenvalue = 3.317, α = 0.797), social cohesion (eigenvalue = 2.633, α = 0.853), and reciprocity (eigenvalue = 1.424, α = 0.732). Confirmatory factor analysis indicated the goodness of fit of this model. Multilevel Poisson regression analysis revealed that civic participation score was robustly associated with individual subjective health (Self-Rated Health: prevalence ratio [PR] 0.96; 95% confidence interval [CI], 0.94–0.98; Geriatric Depression Scale [GDS]: PR 0.95; 95% CI, 0.93–0.97). Reciprocity score was also associated with individual GDS (PR 0.98; 95% CI, 0.96–1.00). Social cohesion score was not consistently associated with individual health indicators. Conclusions Our scale for measuring social capital at the community level might be useful for future studies of older community dwellers.

Oral Health and Incident Depressive Symptoms: JAGES Project Longitudinal Study in Older Japanese

To determine whether oral health status predicts depressive symptoms in older Japanese people.

Community social capital and tooth loss in Japanese older people: a longitudinal cohort study

Objective To date, no study has prospectively examined the association between social capital (SC) in the community and oral health. The aim of this longitudinal cohort study was to examine the association between both community-level and individual-level SC and tooth loss in older Japanese people. Design Prospective cohort study Setting We utilised data from the Japan Gerontological Evaluation Study (JAGES) performed in 2010 and 2013 and conducted in 525 districts. Participants The target population was restricted to non-institutionalised people aged 65 years or older. Participants included 51 280 people who responded to two surveys and who had teeth at baseline. Primary outcome measure The primary outcome measure was loss of remaining teeth, measured by the downward change of any category of remaining teeth, between baseline and follow-up. Results The mean age of the participants was 72.5 years (SD=5.4). During the study period, 8.2% (n=4180) lost one or more of their remaining teeth. Among three community-level SC variables obtained from factor analysis, an indicator of civic participation significantly reduced the risk of tooth loss (OR 0.93; 95% CI 0.88 to 0.99). The individual-level SC variables ‘hobby activity participation’ and ‘sports group participation’ were also associated with a reduced risk of tooth loss (OR 0.88; 95% CI 0.81 to 0.95 and OR 0.90; 95% CI 0.82 to 0.99, respectively). Conclusions Living in a community with rich SC and individuals with good SC is associated with lower incidence of tooth loss among older Japanese people.

Eating Alone Yet Living With Others Is Associated With Mortality in Older Men: The JAGES Cohort Survey

Abstract Objectives Eating by oneself may be a risk factor for poor nutritional and mental statuses among older adults. However, their longitudinal association with mortality in relation to coresidential status is unknown. Method We conducted a 3-year follow-up of participants in the Japan Gerontological Evaluation Study, a population-based cohort of 65 years or older Japanese adults. We analyzed mortality for 33,083 men and 38,698 women from 2010 to 2013 and used. Cox regression models were used to estimate hazard ratios (HR) for mortality. Results A total of 3,217 deaths occurred during the follow-up. Compared with men who ate and lived with others, the HRs after adjusting for age and health status were 1.48 (95% confidence intervals [CI]: 1.26–1.74) for men who ate alone yet lived with others and 1.19 (95% CI: 1.01–1.41) for men who ate and lived alone. Among women, the adjusted HR was 1.18 (95% CI: 0.97–1.43) for women who ate alone yet lived with others and 1.10 (95% CI: 0.93–1.29) for women who ate and lived alone. Discussion A setting in which older adults eat together may be protective for them. Promotion of this intervention should focus on men who eat alone yet live with others.

A 10-Year Follow-Up Study of Social Ties and Functional Health among the Old: The AGES Project

In Asian nations, family ties are considered important. However, it is not clear what happens among older people with no such ties. To investigate the association, we used longitudinal data from the Aichi Gerontological Evaluation Study (AGES) project. Functionally independent older people at baseline (N = 14,088) in 10 municipalities were followed from 2003 to 2013. Social ties were assessed by asking about their social support exchange with family, relatives, friends, or neighbors. Cox proportional hazard models were employed to investigate the association between social ties and the onset of functional disability adjusting for age, health status, and living arrangement. We found that social ties with co-residing family members, and those with friends or neighbors, independently protected functional health with hazard ratios of 0.81 and 0.85 among men. Among women, ties with friend or neighbors had a stronger effect on health compared to their male counterparts with a hazard ratio of 0.89. The fact that social ties with friends or neighbors are associated with a lower risk of functional decline, independent of family support, serves to underscore the importance of promoting social ties, especially among those lacking family ties.