Shuichiro Watanabe

Predictors for Functional Decline Among Nondisabled Older Japanese Living in a Community During a 3‐Year Follow‐Up

OBJECTIVES: To examine predictors for functional decline in basic activities of daily living (BADL) as well as predictors for decline in instrumental activities of daily living (IADL) among nondisabled older Japanese people living in a community during a 3‐year interval from 1992 to 1995.

Longitudinal changes in higher-level functional capacity of an older population living in a Japanese urban community

This study examined the present state and longitudinal changes in higher-level functional capacity in a Japanese urban community. Persons aged 65-84 years living in a suburb of central Tokyo participated in a baseline survey held in 1991 (n = 814) and followed-up for 8 years. Outcome measures were disabilities in: instrumental self-maintenance (IADL), the intellectual activity scale (intellectual activity) and the social role scale (social role), as measured by subscales of the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-index of competence). At baseline among the three subscales, both older men and women had the highest prevalence of disability in social role, followed in turn by intellectual activity and IADL disability. The 8-year longitudinal survey on subjects who had no initial disability (229 men and 235 women) in all three subscales of TMIG-index of competence demonstrated that they were most likely to lose social role function with advancing age, followed in turn by intellectual activity and IADL. The Cox proportional hazard model analysis for all 814 participants revealed that baseline level of social role and intellectual activity significantly predicted the new onset of IADL disability during the 8-year follow-up period even after controlling for gender, age, and chronic medical conditions. In summary, disability in social role and intellectual activity do not only likely precede IADL disability, but also predict significantly the future onset of IADL disability in a Japanese urban community older population.

β2-Microglobulin for Risk Stratification of Total Mortality in the Elderly Population: Comparison With Cystatin C and C-Reactive Protein

BACKGROUND The clinicoepidemiologic relevance of moderately elevated concentrations of circulating beta(2)-microglobulin (beta(2)-M) has not been established. METHODS We examined whether serum beta(2)-M concentration independently predicts total mortality in community-dwelling older populations and compared its predictive value with that of cystatin C and C-reactive protein (CRP) using a prospective cohort study of 1034 initially nondisabled persons 65 years and older as part of the Tokyo Metropolitan Institute of Gerontology Longitudinal Interdisciplinary Study on Aging. Cox proportional hazards models were used to examine independent associations between baseline beta(2)-M levels and total mortality. RESULTS During a median follow-up of 7.9 years, 223 persons died. A strong dose-response relationship was found between baseline serum beta(2)-M concentration and mortality risk, even after multiple adjustments. Compared with individuals in the lowest tertile of serum beta(2)-M concentration, those in the middle (hazard ratio, 2.02; 95% confidence interval [CI], 1.35-3.04) and highest (hazard ratio, 2.84; 95% CI, 1.92-4.20) tertiles had a substantially increased mortality risk. Respective values were 1.28 (95% CI, 0.86-1.90) and 1.95 (95% CI, 1.31-2.89) for cystatin C and 1.39 (95% CI, 0.98-1.98) and 1.44 (95% CI, 1.00-2.06) for CRP; only the highest tertiles showed significantly higher mortality risks. The area under the receiver operating characteristic curve for 8-year mortality was greatest for beta(2)-M (0.70; 95% CI, 0.66-0.74), followed by cystatin C (0.66; 95% CI, 0.62-0.70) and CRP (0.57; 95% CI, 0.53-0.61). Additional adjustment for renal function measures, inflammation markers, or both only partially reduced the association between beta(2)-M and mortality. CONCLUSION Serum beta(2)-M is an independent predictor of total mortality in a general population of older adults and may be a better predictor than cystatin C or CRP.

Predictors for the onset of functional decline among initially non‐disabled older people living in a community during a 6‐year follow‐up

Background:  Predictors for functional decline in basic activities of daily living (BADL) among older people have been extensively studied. However, relatively little is known about predictors for decline in instrumental activities of daily living (IADL).

Association of radial bone mineral density with CA repeat polymorphism at the interleukin 6 locus in postmenoposal Japanese women

AbstractTwin studies have shown strong correlations between bone mass and genetic factors. Some of the genes involved could regulate bone metabolism and bone formation and resorption, all processes that determine bone mass. One candidate gene, interleukin 6 (IL-6), has been implicated in the pathogenesis of bone loss because it stimulates osteoclasts. We investigated a possible association between the CA repeat polymorphism at the IL-6 gene locus and the bone mineral density (BMD) of radial bone in 472 postmenopausal Japanese women. Genotypes were classified into six groups according to the number of CA repeats present, from 13 to 18. BMD was expressed as adjusted BMD, which was the body mass index (BMI)- and age-adjusted average BMD. The 73 women who possessed an A1 allele (134 bp, containing 18 repeats of CA) had significantly lower adjusted BMD than those participants (n = 399) who did not carry an allele of that size (mean ± SD values, 0.294 ± 0.064 vs 0.312 ± 0.061 g/cm2; P = 0.0221). This result suggests that genetic variation at the IL-6 gene locus is associated with some determinants of BMD in postmenopausal women.

Walking speed as a good predictor for maintenance of I‐ADL among the rural community elderly in Japan: A 5‐year follow‐up study from TMIG‐LISA

Background  A population‐based prospective cohort study was undertaken to examine the predictors of functional decline in instrumental activities of daily living (I‐ADL) among non‐disabled older Japanese subjects living in a rural community during a five‐year interval from 1992 to 1997.

The effects of short-term exercise intervention on falls self-efficacy and the relationship between changes in physical function and falls self-efficacy in Japanese older people: a randomized controlled trial.

Arai T, Obuchi S, Inaba Y, Nagasawa H, Shiba Y, Watanabe S, Kimura K, Kojima M: The effects of short-term exercise intervention on falls self-efficacy and the relationship between changes in physical function and falls self-efficacy in Japanese older people: a randomized controlled trial. Am J Phys Med Rehabil 2007;86:133–141. Objective:To evaluate the effects of short-term exercise intervention on falls self-efficacy and to evaluate the relationships between baseline falls self-efficacy and changes in physical function in older people. Design:Single-blinded randomized controlled trial. The participants were 171 subjects aged 65 and older. They were randomly assigned into an exercise intervention group or a health education group. The subjects in the exercise intervention group performed an exercise program for 3 mos. Falls self-efficacy was measured using the falls efficacy scale (FES). The measurements of physical function included static and dynamic balance, walking velocity, flexibility, and strength. Results:There was no significant improvement of FES in either group. But there were significant negative correlations between baseline FES score and the change in maximum walking velocity (r = −0.29, P < 0.018) and knee extensor strength (r = −0.25, P < 0.040. Linear regression analysis showed that the change in static balance was related to baseline FES. Conclusions:The results suggest that a short-term exercise intervention had no effect, possibly because of the high baseline FES scores of the participants, on the confidence of community-dwelling older persons. However, the negative association between FES score and increases in some measures of function suggest that short-term exercise may be beneficial to a subset of older persons with lower FES scores.

Prevalence and characteristics of older community residents with mild cognitive decline

Background:  Cognitive impairment is a major health issue, but epidemiological data on mild cognitive decline have been almost absent in Japan.

Association of bone mineral density with polymorphism of the human matrix Gla protein locus in elderly women

Abstract: The contribution of genetic factors has been implicated in the determination of bone mass in twin and family studies. Some of the genes involved would regulate bone metabolism, bone formation, and resorption, all processes that determine bone mass. One candidate gene, matrix Gla protein gene (MGP), has been implicated in the pathogenesis of bone loss through a repression of bone formation. To analyze the genetic background for osteoporosis in elderly women, we have investigated a possible association between the CA repeat polymorphism at the human MGP gene locus and bone mineral density (BMD) of radial bone in 460 elderly Japanese women. Genotypes were classified into six groups according to the number of CA repeats present, from 13 to 18 (alleles A1 through A6). BMD was expressed as the adjusted BMD (ADJBMD), which was the body mass index (BMI)- and age-adjusted average BMD. The 214 women who lacked an A2 allele (212 bp, containing 17 repeats of CA) had significantly lower adjusted BMD than the participants (n = 246) who possessed an allele of that size (mean ± SD; 0.303 ± 0.062 vs 0.315 ± 0.062 g/cm2; P = 0.0382). This result suggests that genetic variation at the MGP locus is associated with some determinants for BMD in elderly women. Therefore, this locus should serve as one of the genetic markers for osteoporosis.

Changes in TMIG‐Index of Competence by subscale in Japanese urban and rural community older populations: Six years prospective study

Objective:  To examine the longitudinal changes in higher‐level functional capacity in Japanese urban and rural community older populations.