Adiposity, physical activity, and muscle quality are independently related to physical function performance in middle-aged postmenopausal women

作者：Ward Ritacco Christie L^*; Adrian Amanda L; Johnson Mary Ann; Rogers Laura Q; Evans Ellen M

来源：Menopause-The Journal of the North American Menopause Society, 2014, 21(10): 1114-1121.

DOI：10.1097/gme.0000000000000225

• Physical function
• Physical activity
• Body composition
• Muscle quality
• 6-Minute walk
• Timed Up and Go

Objective: Poor physical function performance is associated with risks for disability in late life; however, determinants of physical function are not well characterized in middle-aged women. The aim of this cross-sectional study was to examine the contributions of body composition, physical activity, muscle capacity, and muscle quality to physical function performance. %26lt;br%26gt;Methods: Postmenopausal women (N = 64; mean [SD] age, 58.6 [3.6] y) were assessed for body composition via dual-energy x-ray absorptiometry, for physical activity via accelerometer (steps per day), and for physical function via Timed Up and Go, 30-second chair stand, and 6-minute walk. Leg strength was assessed using isokinetic dynamometry at 60 degrees second(-1). Leg power was assessed with the Nottingham Leg Extensor Power Rig. Muscle quality was calculated as (1) the ratio of leg strength at 60 degrees second(-1) to upper leg lean mass and (2) the ratio of leg power to total lower body lean mass. %26lt;br%26gt;Results: Regression analyses revealed the following: (1) age and muscle quality calculated with leg power are (i)ndependently related to Timed Up and Go, explaining 12% and 11% of the variance, respectively (P %26lt; 0.05); (2) age and muscle quality calculated with leg strength are independently related to 30-second chair stand, explaining 12% and 10% of the variance, respectively (P %26lt; 0.05); and (3) number of medical conditions, muscle quality calculated with leg strength, steps per day, and adiposity are independent predictors of 6-minute walk, collectively explaining 51% of the variance. %26lt;br%26gt;Conclusions: In postmenopausal women, a more optimal body composition (including lower adiposity and higher lean mass) and higher levels of physical activity are associated with better physical function performance at midlife.

• 出版日期2014-10