The Changes of Lower Muscle Strength and Physical Performance in Robust and Pre-frail Outpatient Older Adults

Tsai-Chun Chen ； Ching-Yu Chen ； Chih-Cheng Hsu ； Ssu-Yuan Chen ； Ching-I Chang ； Ming-Hsia Hu

《台灣老年醫學暨老年學雜誌》 9卷2期 (2014/05) Pp. 64-64(2)

並列摘要

Objective: Muscle mass loss, muscle strength decline and poor physical performance, slow gait speed and decreased mobility are characteristics of sarcopenia and the frailty syndrome. Frailty is a dynamic state and it may transit with aging. The purpose of this study was to examine the changes and associations among lower extremity muscle mass and muscle strength observed longitudinally for 3 years in robust and pre-frail outpatient older adults. Methods: This was a 3-year longitudinal cohort study of outpatient older adults recruited from geriatric clinics. Frailty status was characterized according to Fried's Frailty Phenotype. Predicted muscle mass (PMM) of lower extremity was measured by bioelectrical impendence analysis (Tanita BC-418 Pro Segmental Body Composition Analyzer). Cybex Norm dynamometer was used to measure knee extensors and flexors isokinetic muscle strength at 0, 60, and 180 degrees/second. Physical performance was assessed by the 5-times sit-to-stand test (5tSTS), timed up and go test (TUGT) and 5-meter walk test (5MmWT). Data were collected annually and then analyzed by analysis of variance (ANOVA) and Pearson correlation. Results: Overall, 95 subjects (49 males, 46 females) completed all three follow-up examinations. The mean age was 77.48 (±5.79) years. There were 26.3% of subjects in the robust and 73.7% in the pre-frail status. The PMM was significantly decreased in robust older adults (p=0.04), the isokinetic muscle strength of knee extensors at 180 degrees/second decreased significantly both in robust (p=0.005) and pre-frail (p=0.002) group. Regarding physical performance, TUGT was significantly worse in follow up from baseline in both groups (robust p=.05; pre-frail p＜0.001). The change of TUGT from baseline to follow up correlated significantly with the change of isokinetic muscle strength of knee extensors at 0 degrees/second (r=.23, p=0.024). Conclusion: Knee extensor muscle strength was critical for detecting the ageing related changes of muscle strength in robust and pre-frail outpatient older adults. Furthermore, it was significantly related to the ability to stand up, walk, and turn.