BODY MASS INDEX AND INTRAMUSCULAR FAT INFILTRATION IN FRAIL AND NON-FRAIL ELDERLY

Background and objectives: Aging determines several changes in body composition, and is associated with increased fat mass and changes in its distribution pattern. All changes in body composition have importance in the functionality of the elderly, as they culminate in a reduction of muscle with the increase of total body fat, making the elderly more susceptible to a limitation of mobility. The purposes of this study were: To compare the intramuscular fat infiltration in frail and non-frail elderly and to verify its association with muscle mass and body mass index. Methods: Cross-sectional exploratory study. A total of 40 elderly people (10 non-frail men and 10 non-frail women, 10 frail men and 10 frail women) selected at the Geriatrics Outpatient Clinic of the Hospital das Clinicas de Ribeirao Preto. Body weight and height were measured and body mass index (BMI) calculated. Thigh muscle volume (MV) and intramuscular fat infiltration (IMAT) were assessed by nuclear magnetic resonance. Results: The mean BMI, IMAT and MV of the groups were: nonfrail women: 28.8±5.5kg.m-2; 6,84±2,4 % and 150,0±19,2cm3; Frail women: 31.75 ± 5.8 kg.m-2; 11.16±3.5% and 130.8±28.6cm3; Nonfrail men: 26.8±5.1 kg.m-2; 5.75±1.77% and 223.7±15.8 cm3; Frail men: 24.3±5.3kg.m-2, 7.55±2.3% and 237.2±26.8 cm3. In the frail elderly group IMAT had a moderate positive association with BMI (r=0.57, p