Objective: A poor social network and the decline of physical function are known to be critical risk factors for functional decline in older adults. The aim of this study was to investigate the relationships between social network and physical function in Japanese community-dwelling older adults. Methods: Participants were 339 adults aged 65 years or older (mean age : 73.0 years, women :70.2%), living independently in their communities. A self-reported questionnaire was used to assess social network on two different scales-the 6-item Lubben Social Network Scale (6LSNS) and frequency of contact with other people. Handgrip strength, knee extension strength, gait speed, Timed Up and Go Test (TUG) results, and 5-repetition chair stand test (CST) scores were used to determine physical function. A multiple regression analysis that adjusted for confounding factors was used to analyze the relationship between the social network scales and each physical function test. Results: According to the results of a multiple regression analysis, a high 6LSNS score was significantly associated with greater handgrip strength (B = 0.63, p = 0.03), faster CST (B = −0.23, p = 0.01), and faster TUG (B = −0.12, p = 0.03), and high frequency of contact was significantly associated with greater handgrip strength (B = 1.08, p = 0.01). Conclusions: Social network was associated with muscle strength and physical performance. Consequently, older adults with poor social networks require an assessment of physical function, since their physical functions have possibly deteriorated.

Objective: Although elderly inpatients are known to experience decreased physical activity in the morning, falls occur frequently during this time. Gait variability is an evaluation of gait instability and a risk factor for falls. Gait initiation requires complex processes, and it is important to evaluate gait variability not only during steady-state gait but also during gait initiation. However, the effect of the diurnal pattern on variability in gait characteristics is still unknown. The aim of this study was to investigate the effect of the diurnal pattern on initiation and steady-state gait variability in elderly inpatients. Method: Thirty-seven elderly inpatients (28 women; mean age, 79.7 ± 9.5 years) who could walk without support were sampled in this study. The quantitative measure of gait variability was evaluated using the coefficient of variation (CV) based on four consecutive stride durations determined using triaxial accelerometers. Gait characteristics were evaluated during initiation and steady-state gait and defined as initiation CV and steady-state CV, respectively. This measurement was performed at two time points, morning and daytime. Results: There was no significant difference between initiation and steady-state gait characteristics in the daytime condition. However, in the morning condition, the initiation CV was higher than the steady-state CV. Furthermore, the initiation CV was higher in the morning than during daytime (p < 0.01). Conclusion: Our study revealed that the variability of initiation gait is higher in the morning. It may be important to assess the risk of falls, including initiation gait, in the morning.

Objective: To compare the association of cough peak flow (CPF) with aging in community-dwelling older adults and to investigate the relationship between physical fitness and CPF in these individuals. Method: Two hundred twenty two community-dwelling older adults were enrolled. CPF was assessed as a cough function parameter. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1.0) were assessed as respiratory function. Maximal expiratory pressure (MEP) and inspiratory pressure (MIP) were assessed as respiratory muscle strength. The 3-minute walk test (3MWT) performance was assessed as a physical fitness. Participants were divided into the following age groups: 60-64, 65-69, 70-74, 75-79 and 80-89 years. One way analysis of variance were computed for comparison between age group, sex and CPF. Multivariate regression analyses were used to investigate the association of CPF with 3MWT. Results: The value of CPF significantly decreased in the 75-79 and 80-89 years group than 60-64 years group in men and in the 80-89 years group than 65-69 years group in women. The value of CPF were 545.5, 497.2, 403.3, 354.8 and 325.4 L/min in the 60-64, 65-69, 70-74, 75-79 and 80-89-year group in men and 263.4, 278.8, 264.5, 214.0, and 193.6 L/min in the corresponding age groups in women, respectively. 3MWT (p = 0.041) was significantly associated with CPF. Conclusions: Cough function tends to decrease with aging in community-dwelling elderly. Physical fitness is associated with cough function.

The aim of this systematic review and meta-analyses was to calculate the pooled prevalence of sarcopenia based on the Asia Working Group for Sarcopenia (AWGS) criteria among Japanese community-dwelling older adults. Data from 8 studies were used to determine the prevalence of sarcopenia in the overall population and in men; data from 9 studies were used to determine that of women. The pooled prevalence rates of sarcopenia using random-effects models were 9.9% (95% confidence interval [CI], 6.2%-15.4%) overall; 9.8% (95% CI, 6.2%-15.2%) among men; and 10.1% (95% CI, 6.4%-15.5%) among women. These findings would be useful to inform community-based strategies and advanced research addressing sarcopenia prevention.