Association of taurine intake with changes in physical fitness among community-dwelling middle-aged and older Japanese adults: an 8-year longitudinal study.

Introduction: Taurine has diverse valuable biological functions, including antioxidant activity and regulation of osmotic pressure. Maintaining physical fitness from middle age is important for healthy life expectancy. Although taurine administration improves muscle endurance and strength, its role in maintenance remains unclear. We aimed to clarify the longitudinal taurine intake association with fitness changes. Methods: Participants comprised men and women aged ≥40 years who participated in the third (2002-2004; Baseline) and seventh (2010-2012; Follow-up) waves of the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) and completed a 3-day dietary weights recording survey at baseline. A table of taurine content was prepared for 751 foods (including five food groups: Seaweed; Fish and shellfish; Meat; Eggs; and Milk and dairy products) from the Standard Tables of Food Composition in Japan (1,878 foods) 2010. Four physical fitness items (knee extension muscle strength, sit-and-reach, one-leg standing with eyes closed, and maximum walking speed) were measured at baseline and follow-up. We analyzed the association of taurine intake with physical fitness change, employing a general linear model (GLM) and trend tests for baseline taurine intake and follow-up fitness change. Adjustments included baseline variables: sex, age, height, weight, educational level, self-rated health, smoking status, depressive symptoms, and clinical history. Results: The estimated average daily taurine intake (standard deviation) was 207.5 (145.6) mg/day at the baseline. When examining the association with the four physical fitness parameters, higher taurine intake positively increased the change in knee extension muscle strength (T1; 0.1, T2; 0.8, T3; 1.1 (kgf) GLM, p < 0.05; p for trend <0.05) and reduced the decline in knee extension muscle strength in the subgroup analysis of participants aged ≥65 years (T1: -1.9, T2: -1.7, T3: -0.4 kgf; GLM p < 0.05, p for trend <0.05). No relationship was found between taurine intake and the remaining three fitness factors. Conclusion: Estimation of taurine intake showed that dietary taurine intake potentially contributes to the maintenance of knee extension muscle strength over 8 years among Japanese community-dwelling middle-aged and older individuals. This is the first study to investigate the association of dietary taurine intake with muscle strength.

Age-Related Changes in Physical Fitness Among Community-Living Middle-Aged and Older Japanese: A 12-Year Longitudinal Study.

Physical fitness is one of the key factors in healthy aging. Although physical fitness is widely recognized to decline with age, age-related decreases in the individual dimensions of physical fitness in later life are less clear. Purpose: The purpose of the present study was to describe the age-related changes in six fitness components covering a variety of motor dimensions in men and women through a 12-year longitudinal epidemiological study. Method: Participants were randomly selected community-living men (n = 1,139) and women (n = 1,128) aged 40 to 79 years at baseline who were repeatedly tested over a mean (standard deviation) follow-up period of 9.8 (3.4) years with a mean of 4.9 (2.3) examinations. The six physical fitness tests were sit-and-reach, grip strength, sit-ups, one-leg standing, reaction time and leg extension power. The effect of age on each physical fitness task was analyzed using a mixed-effects model controlling for habitual physical activity level. Results: The fixed effect of the interaction of age and time in all fitness tests was significant in men. Higher age at baseline was significantly associated with a greater decrease over time except in one-leg standing. In women, no significant interaction effect of age and time was found in grip strength or reaction time. Age-related changes in grip strength and reaction time were constant with increasing age. Conclusion: Twelve-year longitudinal data showed that the age-related decrease in physical fitness over time, especially musculoskeletal fitness in men, was pronounced, whereas in women, the decrease was less pronounced.

Effectiveness of a home hazard modification program for reducing falls in urban community-dwelling older adults: A randomized controlled trial.

AIM: To evaluate the potential improvement of fall prevention awareness and home modification behaviors and to decrease indoor falls by applying a home hazard modification program (HHMP) in community-dwelling older adults followed up to 1 year in this randomized controlled trial. METHODS: The present authors randomly assigned 130 older adults living in the Tokyo metropolitan region to either the HHMP intervention group (n = 67) or the control group (n = 63). Both groups received four, 2 h fall prevention multifactorial programs including education regarding fall risk factors, food and nutrition, foot self-care, and exercise sessions. However, only the HHMP group received education and practice regarding home safety by using a model mock-up of a typical Japanese home. RESULTS: The mean age of the HHMP group was 75.7 years and the control group 75.8. The HHMP group showed a 10.9% reduction in overall falls, and falls indoors showed an 11.7% reduction at 52 weeks. Those aged 75 years and over showed a significant reduction in both overall falls and indoor falls at 12 weeks. Fall prevention awareness and home modifications were significantly improved in the HHMP group. CONCLUSION: HHMP has the potential to improve fall prevention awareness and home modification behaviors, and specifically decreased overall and indoor falls in 12 weeks in those aged 75 years and older in community-dwelling older adults.

Mobility limitation as a predictor of inpatient care in the last year of life among community-living older people.

BACKGROUND AND AIMS: Need for inpatient care increases toward the end of life. We studied whether mobility limitation assessed approximately 5.8 years prior to death predicts the number of days in care during the last year of life. METHODS: A population-based, prospective study with interviews conducted, on average, 5.8 years prior to death. Data on vital status and health care use were register-based. Participants consisted of 846 persons who had died between 1989 and 2004 at the age of 66-98 years. Participants were categorized as having mobility limitation if, at baseline, they reported difficulties in walking 2 km or climbing one flight of stairs. RESULTS: Mean ± standard deviation of age at death for men was 81.6 ± 6.2 years and the median number of days in inpatient care in the last year of life was 38.5 days. For women, the corresponding figures were 84.1 ± 6.1 years and 66.0 days. Only 11% of men and 7% of women had no inpatient care in the last year of life. The adjusted incidence rate ratio for all-cause inpatient care in the last year of life was 1.53 (95% CI 1.09-2.16) among men with mobility limitation compared to those with intact mobility. Among women, mobility limitation did not increase the risk for all-cause inpatient care. CONCLUSION: Mobility limitation (vs. intact mobility) at 5.8 years prior to death markedly increases the need of inpatient care in the last year of life among men.

Relationship between low free testosterone levels and loss of muscle mass.

We assessed longitudinal relationships between baseline testosterone and muscle mass changes in Japanese men. Data were collected from community-dwelling 957 adult men who participated in a longitudinal study of ageing biennially from 1997-2010. Appendicular muscle mass (AMM) was measured with dual-energy X-ray absorptiometry at baseline and follow-up examinations. The cut-off point of sarcopenia was defined as a skeletal muscle index (AMM/height(2)) < 6.87 kg/m(2). Total testosterone (TT) and free testosterone (FT) were measured with a radioimmunoassay. The calculated FT (cFT) was determined with a formula using albumin, TT, and sex hormone-binding globulin levels. We analyzed 4,187 or 2,010 cumulative data points using generalized estimating equations. Low TT was not associated with sarcopenia. Low cFT (odds ratio = 2.14, 95% confidence interval: 1.06-4.33) and FT (odds ratio = 1.83, 95% confidence interval: 1.04-3.22) were associated with sarcopenia. Low FT may be a predictor of risk for muscle loss in Japanese men.

Relationship between physical activity and brain atrophy progression.

INTRODUCTION: Brain atrophy is associated with impairment in cognitive function and learning function. The aim of this study was to determine whether daily physical activity prevents age-related brain atrophy progression. METHODS: The participants were 381 men and 393 women who had participated in both the baseline and the follow-up surveys (mean duration = 8.2 yr). Magnetic resonance imaging of the frontal and temporal lobes was performed at the time of the baseline and follow-up surveys. The daily physical activities and total energy expenditures of the participants were recorded at baseline with uniaxial accelerometry sensors. Multiple logistic regression models were fit to determine the association between activity energy expenditure, number of steps, and total energy expenditure variables and frontal and temporal lobe atrophy progression while controlling for possible confounders. RESULTS: In male participants, the odds ratio of frontal lobe atrophy progression for the fifth quintile compared with the first quintile in activity energy expenditure was 3.408 (95% confidence interval = 1.205-9.643) and for the number of steps was 3.651 (95% confidence interval = 1.304-10.219). Men and women with low total energy expenditure were at risk for frontal lobe atrophy progression. There were no significant differences between temporal lobe atrophy progression and physical activity or total energy expenditure. CONCLUSION: The results indicate that physical activity and total energy expenditure are significant predictors of frontal lobe atrophy progression during an 8-yr period. Promoting participation in activities may be beneficial for attenuating age-related frontal lobe atrophy and for preventing dementia.

Spatiotemporal components of the 3-D gait analysis of community-dwelling middle-aged and elderly Japanese: age- and sex-related differences.

AIM: To describe age- and sex-related differences in gait patterns of community-living men and women using 3-D gait analysis. METHODS: Subjects (n=2006) aged 40-84 years participated in the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA). Spatiotemporal components, including velocity, step length, step frequency, and double support time during a gait cycle, were calculated from 3-D coordinates and vertical force data. Velocity, step length and step frequency were normalized by leg length and acceleration due to gravity, and double support time was normalized to gait cycle duration. RESULTS: Spatiotemporal walking variables of brisk velocity and step length were significantly greater in men than in women, while comfortable velocity and comfortable and brisk step frequencies and double support times were greater in women than in men. Age-related changes were marked at 70-84 years in most spatiotemporal variables in both sexes during comfortable walking. During brisk walking, age-related changes were observed from a younger age than during comfortable walking, and there were sex-related differences. CONCLUSION: The age-related gait alteration was obvious among those aged 70 years and older, and it accelerated markedly in women's brisk walking intensity.

Social support as a moderator in a fall prevention program for older adults.

This study examined the moderating effects of social support in a fall prevention program for community-dwelling older adults. Twenty-six Japanese older adults age 65 and older participated in a 2-month exercise program and were measured in anthropometrical, physical, and psychological functioning at baseline, 2 months (intervention termination), and 5 months (3 months after intervention termination). Analyses indicated that the program did not improve participants' body mass index, balance, or walking speed. However, participants'falls self-efficacy significantly increased from baseline to intervention termination and was maintained at a higher level at the 5-month postintervention follow up. This efficacy-improving effect was prominent in the participants who had received less social support at baseline. The findings emphasized the importance of considering participants' social resources and targeted intervention outcomes when evaluating the effect of exercise.

Segmental dynamics of soccer instep kicking with the preferred and non-preferred leg.

Detailed time-series of the resultant joint moments and segmental interactions during soccer instep kicking were compared between the preferred and non-preferred kicking leg. The kicking motions of both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The resultant joint moment (muscle moment) and moment due to segmental interactions (interaction moment) were computed using a two-link kinetic chain model composed of the thigh and lower leg (including shank and foot). The mechanical functioning of the muscle and interaction moments during kicking were clearly illustrated. Significantly greater ball velocity (32.1 vs. 27.1 m . s(-1)), shank angular velocity (39.4 vs. 31.8 rad . s(-1)) and final foot velocity (22.7 vs. 19.6 m . s(-1)) were observed for the preferred leg. The preferred leg showed a significantly greater knee muscle moment (129.9 N . m) than the non-preferred leg (93.5 N . m), while no substantial differences were found for the interaction moment between the two legs (79.3 vs. 55.7 N . m). These results indicate that the highly skilled soccer players achieved a well-coordinated inter-segmental motion for both the preferred and non-preferred leg. The faster leg swing observed for the preferred leg was most likely the result of the larger muscle moment.

Age differences in the effect of physical activity on depressive symptoms.

This study examined associations between physical activity and depressive symptoms in 1,151 community-dwelling adults in Japan. Physical activity was measured using a pedometer, whereas depressive symptoms were assessed with the Center for Epidemiological Studies-Depression Scale. A structural equation modeling with a cross-lagged panel design revealed that for the older adults (65-79 years of age), daily walking at baseline predicted fewer depressive symptoms at the 2-year follow-up, even after adjusting for confounders. In contrast, the association was not confirmed for the middle-aged adults (40-64 years of age). Findings suggest that age should be considered when estimating the effect of physical activity on psychological well-being.

[Epidemiology of falls among community-dwelling elderly people].

The purpose of the present study was to report the prevalence and circumstances of falls among community-dwelling elderly people in order to contribute to prevention of falls in the community. The subjects were 2,774 elderly people who participated in health examinations conducted by Tokoname-shi, Aichi Prefecture in 2002. The variables investigated in the present study were demography and history of falls in the past one-year. Circumstances of falls, e.g. time, location, activities associated with falls, cause of falls and degree of injury due to falls were asked when the subjects experienced a fall. The prevalence of falls among 2,774 subjects was 13.7%. It was significantly higher among women (17.2%) than men (8.3%, chi 2 = 48.1, p < 0.001). Prevalence increased as subjects get older. Circumstances of falls were assessed in 655 subjects. The distribution of time, location, activity associated with falls, cause and injury due to falls corresponded with previous fall studies among community dwelling elderly people. The incidence of falls was extremely high during the daytime and outdoors. Falls occurred most frequently while walking. The majority of falls were due to extrinsic factors. About 10% of all falls caused fracture.