Prevalenza della sarcopenia in una popolazione napoletana di anziani obesi e trattamento nutrizionale

Background: A reduction in muscle mass (MM), known as sarcopenia, and an increase in fat mass is one of the most striking and consistent changes associated with obesity in aging. Sarcopenia should be evaluated in older patients who present declines in physical activity and strength. A careful weight management may be useful to reduce fat mass and to preserve muscle mass in sarcopenic obese old patients. Objective: The main purpose of our study was to diagnose sarcopenia in obese older peoples and to assess the effect of a diet moderately rich in proteins on lean mass loss in sarcopenic obese older patients. Material and Methods: 1814 patients (1301 females, 20-75 years old) were enrolled in the study to determine new cut-off of muscle mass index (MMI) to evaluate sarcopenia. 1272 subjects (1030 females - age > 65 years; BMI > 30 Kg/m2) were recruited to verify the effect of a diet moderately rich in proteins (1,2 g/Kg/die) on lean mass loss in sarcopenic obese older patients. Nutritional status was assessed and MM was estimated. MMI was calculated as: MM/height2 in all populations. Results: MMI was significantly different in males and females, according to obese and normalweight conditions, as well as age. New MMI cut-off were calculated (as MMI †" 2SD) in all groups. In particular, in obese adult men MMI cut-off was 8,54 Kg/m2, while it was 7,89 Kg/m2 in normalweight adult men. MMI cut-off was 7,28 Kg/m2 in obese adult women and 6,79 Kg/m2 in normalweight adult women. According to obese-derived MMI cut-off scores, 104 obese older women (out of 1030) and 9 obese older men (out of 242) were classified as sarcopenic. After dieting (1,2 g/Kg/die of proteins), significant reductions in BMI were detected in all sarcopenic populations (Females: 30,26 ± 0,02 vs 31,05 ± 0,03 Kg/m2; Males: 29,2 ± 0,4 vs 30,20 ± 0,03 Kg/m2, p < 0,01 vs baseline). MMI showed a significant increase in sarcopenic obese older women (7,13 ± 0,01 vs 6,96 ± 0,01 Kg/m2, p<0,01 vs baseline), but not in sarcopenic obese older men (8,8 ± 0,3 vs 8,27 ± 0,04 Kg/m2). Moreover, AMA did not present significant variations in all sarcopenic groups (Females: 43,11 ± 0,04 vs 43,59 ± 0,05 cm2; Males: 53,2 ± 4,0 vs 51,9 ± 3,3 cm2). Conclusions: MMI was significantly different in males and females, comparing obese and normalweight groups. In particular, MMI in our obese patients was higher than in normalweight peoples. New cut-off, derived from obese adult population, may be useful to estimate sarcopenia in obese older peoples. Diet moderately rich in proteins appeared to preserve muscle mass in sarcopenic subjects. Therefore, adequate protein intake could contribute to prevent lean mass loss associated with weight loss in obese older patients.