Effects of exercise habits in adolescence and older age on sarcopenia risk in older adults: the Bunkyo Health Study.

Background: Sarcopenia, defined as an age-associated loss of skeletal muscle mass and function, is a major risk factor for requiring long-term care. Because physical activity in adolescence and older age enhances peak muscle function in youth and prevents muscle function decline in older age, older adults with exercise habits during both periods may be at a lower risk for sarcopenia. We investigated the relationship between exercise habits in adolescence and older age and sarcopenia and its components in community-dwelling older Japanese adults.

Methods: This study included 1607 community-dwelling individuals (aged 65-84, medians 73 years, 679 men and 928 women) with complete health examinations, including measurements of skeletal muscle index, handgrip strength and gait speed, who were enrolled in the Bunkyo Health Study. We divided the participants into four groups according to exercise habits in adolescence and older age: no exercise in either period (none-none; NN), exercise only in adolescence (active-none; AN), exercise only in older age (none-active; NA) and exercise in both periods (active-active; AA). Multivariate-adjusted logistic regression models were used to estimate the odds ratios (ORs) and associated 95% confidence intervals (CIs) in each group for the prevalence of sarcopenia, defined as low muscle mass and low muscle performance, as compared with the NN group. Low muscle performance was defined as low muscle strength and/or low gait speed.

Results: The total prevalence of sarcopenia was 6.6% (45/679) in men and 1.7% (16/928) in women, the total prevalence of low muscle mass was 14.3% (97/679) in men and 5.2% (48/928) in women, and the total prevalence of low muscle performance was 25.6% (174/679) in men and 19.6% (182/928) in women. In men, the ORs (95% CIs) for sarcopenia, low muscle mass and low muscle performance were significantly lower in the AA group (sarcopenia: 0.29 [0.09-0.95], P = 0.041; low muscle mass: 0.21 [0.09-0.52], P = 0.001; and low muscle performance: 0.52 [0.28-0.97], P = 0.038). In women, the OR (95% CI) for low muscle performance was significantly lower in the AA group than in the other groups (0.48 [0.27-0.84], P = 0.010), whereas none of the ORs for sarcopenia and low muscle mass were significant.

Conclusions: Older men with exercise habits in both adolescence and older age were at a lower risk of sarcopenia, low muscle mass and low muscle performance, whereas older women with exercise habits at both time periods were at a lower risk of low muscle performance.