Handgrip strength, quadriceps muscle power, and optimal shortening velocity roles in maintaining functional abilities in older adults living in a long-term care home: a 1-year follow-up study

摘要

Purpose: To assess the relative role of handgrip strength (HGS), quadriceps muscle power (P_max), and optimal shortening velocity (υ_opt) in maintaining functional abilities (FAs) in older adults living in a long-term care home over a 1-year follow-up. Subjects and methods: Forty-one inactive older institutionalized adults aged 69.8±9.0?years participated in this study. HGS, P_max, υ_opt, cognitive function using the Mini-Mental State Examination, depressive symptoms using the Geriatric Depression Scale, nutritional status using the Mini Nutritional Assessment (MNA), and physical activity (PA) using the Seven-Day Physical Activity Recall Questionnaire were assessed at baseline and at 1-year follow-up. FAs were assessed with activities of daily living (ADL), instrumental ADL, and Timed Up & Go test. Results: Both at baseline and at follow-up, FAs were related to age, HGS, P_max/kg, υ_opt, MNA, and PA. These associations were generally similar in both sexes. As revealed in multiple regression analysis, υ_opt was the strongest predictor of FA, followed by P_max/kg, PA, and MNA. FA deteriorated after 1?year as measured by ADL and Timed Up & Go test. P_max and υ_opt, but not HGS, also decreased significantly after 1?year. Nevertheless, 1-year changes in FAs were not related to changes in HGS, P_max, υ_opt, or PA. Conclusion: The 1-year period of physical inactivity among older institutionalized adults was found to have a negative effect on their FAs, P_max, and υ_opt. The present study demonstrates that P_max and, especially, υ_opt correlated with FAs of older adults more than HGS, both at baseline and at follow-up. Despite this, 1-year natural fluctuations of PA, P_max, and υ_opt are not significant enough to influence FAs in inactive institutionalized older adults.