Muscle strength to body weight ratio is a better predictor of low physical function than absolute muscle strength in postmenopausal women / A força muscular corrigida pela massa corporal é um preditor melhor da baixa função física do que a força muscular absoluta em mulheres na pós-menopausa

ABSTRACT

Objective: We investigated the predictive contributions and diagnostic accuracy of muscle strength (MS) and muscle strength to body weight ratio (MS/BW) on physical function in postmenopausal women (PW). Methods: This cross-sectional study evaluated forty-nine sedentary PW (61.7 ± 7.9 years). Body weight and height were measured with a digital scale and a stadiometer respectively. Muscle strength was determined by manual dynamometer and the left and right hand values were summed. Physical function was assessed by the six-minute walk test, short physical performance battery (SPPB) and Quality of Life Questionnaire (SF-36). A composite measure of physical function was calculated by summing the Z scores (x-µ/σ) of each individual assessment to provide a global index of physical function. Results: Muscle strength-specific linear regression analyses indicated that the strongest predictor of physical function was MS/BW [Beta of Z score = 0.91±0.07 (SE)] when compared to MS [Beta of Z score = 0.59±0.13 (SE)]. The ROC curve values indicated that the more accurate measure of physical function (P = 0.026) was MS/BW [AUC = 0.91±0.04 (SE)] when compared to MS [AUC = 0.75±0.08 (SE)]. Conclusion: The findings of this study suggest that MS/ BW is more accurate and predictive measure of low physical function than absolute MS in PW