Hajime Iwasa

Brief screening tool for mild cognitive impairment in older Japanese: Validation of the Japanese version of the Montreal Cognitive Assessment

Aim:  The Montreal Cognitive Assessment (MoCA), developed by Dr Nasreddine (Nasreddine et al. 2005), is a brief cognitive screening tool for detecting older people with mild cognitive impairment (MCI). We examined the reliability and validity of the Japanese version of the MoCA (MoCA‐J) in older Japanese subjects.

Low serum 25-hydroxyvitamin D levels associated with falls among Japanese community-dwelling elderly.

Previous studies have shown that low serum 25‐hydroxyvitamin D [25(OH)D] level is a risk factor for falls among the elderly in European and North American populations. We used a cross‐sectional community‐based survey to study the association of serum 25(OH)D level and falls among Japanese community‐dwelling elderly. A total of 2957 elderly persons (950 men and 2007 women) 65–92 yr of age who participated in mass health examinations for the prevention of geriatric syndrome for the elderly underwent an interview, blood analysis, and physical performance testing. Experience of falls over the previous year was assessed in an interview. Physical performance tests of handgrip strength, stork standing time with the eyes open, and normal waking speed as risk factors for falls among the elderly were conducted. Serum albumin and 25(OH)D concentrations were analyzed. Mean 25(OH)D concentration was significantly lower in women than in men (p < 0.001). Women showed a significant decline of 25(OH)D level with increased age (p < 0.001). There was also a significant difference in the prevalence of 25(OH)D insufficiency [25(OH)D level < 20 ng/ml] between the sexes (p < 0.001). The rate of falls was significantly higher in the lowest quartile of 25(OH)D level in women (p = 0.02) and in women with 25(OH)D insufficiency (p = 0.001). Women also showed significant declines in all three fall‐related physical performance tests. Multiple logistic regression analysis showed significant and independent associations between 25(OH)D level and experience of falls in women only (p = 0.01). Low 25(OH)D level was significantly associated with a high prevalence of falls in Japanese elderly women because of their inferior physical performance. Low serum 25(OH)D levels appear preventable and easily treated; there is an evident need for greater awareness to screen and thus prevent this condition.

Depression status as a reliable predictor of functional decline among Japanese community-dwelling older adults: a 12-year population-based prospective cohort study

This study aimed to examine a longitudinal relationship between depression status and functional decline among Japanese community‐dwelling older adults, using a 12‐year population‐based, prospective cohort study design.

Concomitant Lower Serum Albumin and Vitamin D Levels Are Associated with Decreased Objective Physical Performance among Japanese Community-Dwelling Elderly

Background: Previous studies have shown that serum albumin or vitamin D is associated with physical performance. We hypothesized that older adults with concomitant lower serum albumin and vitamin D (25-hydroxyvitamin D, 25OHD) levels are associated with decreased physical performance compared to those with 1 or none of the 2 risk factors. Objective: To investigate the association of combined serum albumin and 25OHD levels with physical performance (muscle strength and balance capability) in community-dwelling elderly. Methods: A cross-sectional study in a community-based population in the province of Tokyo, Japan, was performed. For the study, 1,094 community-dwelling people aged 70 and older underwent an interview, anthropometric measurements, blood analysis and physical performance testing. The subjects were classified into 4 types by combining serum albumin and 25OHD levels: lower albumin only, lower vitamin D only, lower albumin and lower vitamin D, higher albumin and higher vitamin D. Results: Men with concomitant lower albumin and lower 25OHD levels had significantly decreased knee extension power, usual timed Up & Go and maximal timed Up & Go, even after adjusting for age and body mass index (BMI). In women, concomitant lower albumin and lower vitamin D was associated with significantly decreased handgrip strength and functional reach, even after adjusting for age and BMI. Subjects with combined lower albumin and lower vitamin D levels showed a significant decline in muscle strength and balance capability compared to higher albumin and higher vitamin D, even after adjusting for age, current drinking or smoking status, physical activity, history of chronic disease, basic activities of daily living, instrumental activities of daily living, BMI and bone mineral density. Conclusion: Concomitant lower serum albumin and lower vitamin D levels are associated with decreased muscle strength and balance capability in both men and women. These results suggest that serum albumin and 25OHD together may be an important target for strategies aiming to achieve a healthy life and prevent loss of independence in community-dwelling elderly.

Leisure activities and cognitive function in elderly community-dwelling individuals in Japan: A 5-year prospective cohort study

OBJECTIVE This study aimed to clarify the longitudinal relationship between leisure activities and cognitive decline among Japanese community-dwelling older adults, using a 5-year prospective cohort study design. METHODS A total of 567 men and women, aged 70years and over, participated in the study. The Mini-Mental State Examination was used in baseline and follow-up surveys to assess cognitive function. The change in cognitive function from baseline to follow-up was determined, and cognitive decline over 5years was used as the outcome variable. Leisure activities (hobby, social activity, and physical activity) were assessed at baseline and used as independent variables. Age, gender, number of years of education, presence of chronic diseases, instrumental activities of daily living, depressive symptoms, smoking, hearing deficits, and level of cognitive function at baseline were used as covariates. RESULTS Multivariate logistic regression analysis, adjusted for potential confounders, showed that non-participation in a hobby was significantly and independently associated with cognitive decline (odds ratio: 1.87, 95% confidence interval: 1.16-3.02, p<0.01). There were no significant relationships between social activity, physical activity and cognitive decline. CONCLUSIONS Our study found a longitudinal inverse relationship between hobby participation and cognitive decline among elderly Japanese community-dwelling individuals, suggesting that engaging in a hobby in later life can contribute to preserving cognitive function.

Declines in Physical Performance by Sex and Age Among Nondisabled Community-Dwelling Older Japanese During a 6-Year Period

Background Few studies have examined whether declines over time in hand-grip strength (HGS) and fast walking speed (FWS) differ by sex and age among non-Western community-dwelling older adults. This study aimed to quantify changes in HGS and FWS over the 6-year period from 1994 to 2000 and examine whether these changes differed by sex and baseline age among older individuals in a Japanese community. Methods We conducted a community-based prospective cohort study. The participants were 513 nondisabled men and women aged 67 to 91 years at the 1994 survey. Independent variables regarding time since baseline, in addition to various time-dependent and time-independent covariates, were obtained in 1994, 1996, 1998, and 2000. The outcome variables were HGS and FWS assessed at each survey. All data on independent and dependent variables that were collected at each survey were simultaneously analyzed using a linear mixed-effects model. Results The linear mixed-effects model revealed significant declines in both HGS (−0.70 kg/year, P < 0.001) and FWS (−0.027 m/sec/year, P < 0.001) among nondisabled older participants who had analyzable data in any survey during the 6-year period. Sex was significantly associated with the rate of decline in HGS (P < 0.001), but not FWS (P = 0.211). Conclusions In this analysis of nondisabled older Japanese, a mixed-effects model confirmed a significant effect of aging on declines in HGS and FWS and showed that men had a significantly steeper decline in HGS than did women during a 6-year period.

Subjective well-being as a predictor of all-cause mortality among middle-aged and elderly people living in an urban Japanese community : A seven-year prospective cohort study

Background:  Research has reported a close relationship between subjective well‐being and maintenance of physical and psychological health in later life. We explored an intergender difference in subjective well‐being, correlates of subjective well‐being, and a subjective well‐being–mortality association among middle‐aged and elderly people, using a prospective population‐based study.

A mortality comparison of participants and non-participants in a comprehensive health examination among elderly people living in an urban Japanese community

Background and aims: Recent studies have revealed that there are critical differences between participants and non-participants in health examinations. The aim of this study was to examine mortality differences between participants and non-participants in a comprehensive health examination for prevention of geriatric syndromes among community-dwelling elderly people, using a three-year prospective cohort study. Methods: The study population included 854 adults aged 70 to 84 at baseline. The following items were all studied: the status of participation in the comprehensive health examination as an independent variable, age, gender, number of years of education, living alone, presence of chronic diseases, experience of falls over one year, history of hospitalization over one year, self-rated health, body mass index, instrumental activities of daily living, and subjective well-being as covariates; and all-cause mortality during a three-year follow-up as a dependent variable. Results: In an adjusted Cox’s proportional hazard regression model, the mortality risk for participants in the comprehensive health examination was significantly lower than that of non-participants (Risk Ratio (for participants)=0.44, 95% confidence interval=0.24 to 0.78). Conclusions: The present study shows that there is a large mortality difference between participants and non-participants. Our findings suggest two possible interpretations: 1) There is a bias due to self-selection for participation in the trial, which was not eliminated by adjustment for the covariates in the statistical model; 2) There is an intervention effect associated with participation in the comprehensive health examination which reduces the mortality risk.

A Significant Relationship between Plasma Vitamin C Concentration and Physical Performance among Japanese Elderly Women

BACKGROUND Maintenance of physical performance could improve the quality of life in old age. Recent studies suggested a beneficial relationship between antioxidant vitamin (eg, vitamin C) intake and physical performance in elderly people. The purpose of this study was to examine the relationship between plasma vitamin C concentration and physical performance among Japanese community-dwelling elderly women. METHODS This is a cross-sectional study involving elderly females residing in an urban area in Tokyo, Japan, in October 2006. We examined anthropometric measurements, physical performance, lifestyles, and plasma vitamin C concentration of participants. RESULTS A total of 655 subjects who did not take supplements were analyzed. The mean age (±standard deviation) of participants was 75.7 ± 4.1 years in this study. The geometric mean (geometric standard deviation) of plasma vitamin C concentration was 8.9 (1.5) μg/mL. The plasma vitamin C concentration was positively correlated with handgrip strength, length of time standing on one leg with eyes open and walking speed, and inversely correlated with body mass index. After adjusting for the confounding factors, the quartile plasma vitamin C level was significantly correlated with the subjects handgrip strength (p for trend = .0004) and ability to stand on one leg with eyes open (p for trend = .049). CONCLUSIONS In community-dwelling elderly women, the concentration of plasma vitamin C related well to their muscle strength and physical performance.

Longitudinal association between habitual physical activity and depressive symptoms in older people

Prevention of depressive symptoms is an essential issue with regard to the promotion of healthy lifestyles in older people. To date, few studies have examined the relation between fluctuations in physical activity and depression among older individuals. We thus conducted a longitudinal survey of older adults to examine the effect of long‐term fluctuating physical activity on the incidence of depressive symptoms.