Higher gait speed and smaller sway area decrease the risk for decline in higher-level functional capacity among middle-aged and elderly women

Abstract

ObjectiveThis study assessed whether physical function can indicate a risk of decline in higher-level functional capacity. MethodsData were derived from the National Institute for Longevity Sciences—Longitudinal Study of Aging. Subjects comprised 466 men and 495 women aged 40–79 years at baseline (1997–2000), whose total score for the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) at baseline was ≥11 and who participated in the follow-up survey. Baseline physical function examination included grip strength, comfortable gait speed, and sway area with eyes open. A decline in higher-level functional capacity was defined as a ≥2-point decrease in the TMIG-IC score after 14 years. The odds ratios (OR) and 95% confidence intervals (CI) for decline in the TMIG-IC score for 14 years according to a 1-standard deviation (SD) increase in physical function measurements at baseline were estimated. ResultsSubjects with decreased TMIG-IC scores included 78 (16.7%) men and 80 (16.2%) women. In women, the multivariate-adjusted OR (95% CI) for a TMIG-IC score decrease with a 1-SD increase in comfortable gait speed was 0.68 (0.50–0.92; p=0.013), and that with a 1-SD increase in sway area with eyes open was 1.49 (1.17–1.90; p=0.001). Grip strength was not associated with TMIG-IC score decline. None of the physical performance measures affected TMIG-IC score declines in men. ConclusionThese results suggest that gait speed decreases and sway area increases might predict a risk of decline in higher-level functional capacity among middle-aged and elderly women.