Main content area

Prevalence of low muscle mass according to body mass index in older adults

Graf, Christophe E., Pichard, Claude, Herrmann, François R., Sieber, Cornel C., Zekry, Dina, Genton, Laurence
Nutrition 2017 v.34 pp. 124-129
bioelectrical impedance, body mass index, elderly, hospitals, lean body mass, men, muscles, odds ratio, skeletal muscle, therapeutics, women
Low muscle mass has been associated with increased morbi-mortality and should be identified for optimizing preventive and therapeutic strategies. This study evaluates the prevalence of bioelectrical impedance analysis (BIA)-derived low muscle mass in older persons using definitions found through a systematic literature search and determines the link between body mass index (BMI) and low muscle mass.We performed a systematic search of trials involving ≥100 persons that derived low muscle mass from BIA and reported cut-offs for low muscle mass normalized for body height or weight. These cut-offs were applied to all adults ≥65 y who underwent a BIA measurement at Geneva University Hospital between 1990 and 2011 (N = 3181). The association between BMI and low muscle mass was evaluated through multivariate logistic regressions.We identified 15 cut-offs based on the fat-free mass index (FFMI), skeletal muscle index (SMI), or skeletal muscle percentage (SMP). Depending on the definition, the prevalence of low muscle mass was 17% to 68% in women and 17% to 85% in men. The risk of low muscle mass increased with a BMI <18.5 kg/m² when using cut-offs based on FFMI (odds ratio [OR] ♀ 14.28–24.04/♂ 25.42–50.64) or SMI (OR ♀ 3.56–4.56/♂ 7.07–8.87) and decreased with a BMI ≥25 kg/m² (FFMI: OR ♀ 0.03–0.04/♂ 0.01–0.04; SMI: OR ♀ 0.18–0.25/♂ 0.14–0.18). The opposite association appeared between BMI and cut-offs based on SMP.The prevalence of low muscle mass varies widely depending on the definition, especially in persons with BMI <18.5 or ≥25 kg/m².