[Descriptive epidemiology of accelerometer-measured moderate to vigorous physical activity in Japanese older adults]

Association of life-space with light-intensity and moderate to vigorous-intensity physical activity in older adults using daycare rehabilitation facilities

BACKGROUND

The use of assistive devices and the presence of caregivers in the living space of older people using daycare rehabilitation facilities may increase their physical activity. However, the exact relationship between these factors and physical activity has not been well established.

OBJECTIVE

We aimed to examine whether assistive devices and caregivers were life-space factors associated with light-intensity physical activity (LPA) and moderate to vigorous-intensity physical activity (MVPA) among daycare rehabilitation facility users.

METHODS

Forty-seven daycare rehabilitation facility users were recruited (mean age: 76.5 ± 8.6 years; men: 16; women: 31). LPA and MVPA were measured using accelerometers and averaged over 7 days. Life-space assessment (LSA) and the Geriatric Depression Scale score were assessed. The LSA includes composite life-space, maximal life-space (LS-M), life-space using equipment (LS-E), and independent life-space. Grip strength and maximum gait speed were measured two times, and the best results were used.

RESULTS

Multiple regression analysis showed that LPA was significantly associated with sex (β = 0.773), grip strength (β = 0.434), and LS-M (β = 0.325), whereas MVPA was significantly associated with age (β = -0.421) and LS-E (β = 0.455).

CONCLUSION

A close association was found between LS-M and LS-E and the intensity of physical activity in older people who used daycare rehabilitation facilities.

Linear and non-linear associations of device-measured sedentary time with older adults' skeletal muscle mass

BACKGROUND

Time spent sitting is associated adversely with health outcomes in older adults. Nevertheless, it is not clear how sedentary time may be related to appendicular skeletal muscle mass (ASM) - a key attribute of sarcopenia. This cross-sectional study examined associations of total sedentary time with ASM among community-dwelling older Japanese males and females.

METHODS

Participants (n = 281, 74.3 ± 5.2 yr) wore a tri-axial accelerometer for seven days. Body mass index-adjusted ASM (kg/BMI) was derived from bioimpedance measures. Multivariate linear and quadratic regression models examined the associations of ASM with total sedentary time, stratified by sex. Restricted cubic spline models were fitted to estimate non-linear associations. Isotemporal substitution (IS) models were used to estimate the impacts of replacing 30-minute of sedentary time with light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA).

RESULTS

After adjustment, total sedentary time had a significant linear and negative association with ASM among females (β = -0.014; p = 0.023). For males, total sedentary time had a significant quadratic association (p = 0.020). Spline models indicated a reverse U-shaped association (p < 0.001) with total sedentary time over 9.3 h/day being associated with lower ASM. The IS models indicated that replacing 30 min/day of sedentary time with LPA would be positively and significantly associated with older females' ASM (β = 0.007, p = 0.022).

CONCLUSIONS

In older Japanese adults, higher volumes of time spent sedentary were associated with lower ASM. For males, only very high volumes of sedentary time appeared to be detrimental. These adverse relationships may in part be offset by more time spent in either LPA or MVPA.

Association between the type of physical activity and metabolic syndrome in middle-aged and older adult residents of a semi-mountainous area in Japan

BACKGROUND

Physical activity is reported to prevent metabolic syndrome. However, it is unclear whether exercise or daily physical activity is more beneficial for residents of semi-mountainous areas. This study aimed to identify whether daily physical activity is more beneficial than exercise for the prevention of metabolic syndrome among middle-aged and older residents in semi-mountainous areas.

METHODS

We analyzed secondary data of 636 people who underwent a specific health checkup in a semi-mountainous area of Japan. Physical activity was classified into four types: inactivity (I-type; without exercise and without daily physical activity), only exercise (E-type; with exercise and without daily physical activity), only daily physical activity (D-type; without exercise and with daily physical activity), and full physical activity type (F-type; with exercise and with daily physical activity). We compared the means of risk factors for metabolic syndrome by these four types, followed by logistic regression analysis, to identify whether and to what extent the D-type was less likely to have metabolic syndrome than the E-type.

RESULTS

The prevalence of metabolic syndrome was 28.5% (men 45.7%, women 15.8%). The proportions of men with exercise and daily physical activity were 38.7% and 52.8%, respectively. For women, the proportions were 33.0% and 47.1%, respectively. In women, the D-type had the significantly lowest BMI, smallest waist circumference, highest HDL-C, and lowest prevalence of metabolic syndrome of the four types; the same was not observed in men. Additionally, D-type activity was more strongly associated with a reduced risk of metabolic syndrome than E-type activity in women (adjusted odds ratio 0.24; 95% confidence interval 0.06-0.85, P = 0.028).

CONCLUSIONS

Compared to middle-aged and older women residents with exercise in a semi-mountainous area of Japan, those with daily physical activity may effectively prevent metabolic syndrome.

Bout Length-Specific Physical Activity and Adherence to Physical Activity Recommendations among Japanese Adults

We aimed to clarify the patterns of moderate to vigorous physical activity (MVPA) in the Japanese adult population, and the proportion of people meeting the recommendations of the Physical Activity Guidelines (PAG) for Americans, second edition (2nd PAG; ≥150 min/week of total MVPA including bouts of any length) and those meeting the previously recommended PAG (2008-PAG; of ≥150 min/week of total MVPA lasting 10 min or longer [long-bout MVPA]). A total of 204 adults (aged 18 to 64 years) from two workplaces were asked to wear an accelerometer. MVPA was classified by bout length, and the proportion of long-bout MVPA was clarified. The proportion of participants adhering to the 2008-PAG and the 2nd PAG recommendations was calculated. Valid data was obtained from 184 adults. Long-bout MVPA accounted for 13.4% of total MVPA. Our results showed that 12.5% of individuals performed MVPA as recommended by the 2008-PAG whereas 92.4% performed MVPA as recommended by the 2nd PAG. Our results, hence, showed that long-bout MVPA comprised only a small proportion of total MVPA, and the proportion of individuals who satisfied the criteria stated in the guidelines (≥150 min/week) significantly changed by whether or not bout length of MVPA was taken into account.