Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Elderly Body Composition and Muscle Strength: A Review of Clinical Trials.

BACKGROUND The aging process has great impact on body composition, such as the increase of adipose tissue in abdominal region, and the decrease of lean body mass, due to skeletal muscle loss. A reduction in muscle mass is associated to high risk of fractures and falls, loss of mobility, and increased number of hospitalizations. Beta-hydroxy-beta-methylbutyrate (HMB) is a biological substance derived from leucine metabolism, with anabolic and anticatabolic properties. Some HMB effects are tissue repair stimulation and protein anabolism. AIMS We aimed to evaluate the effects of HMB supplementation on body composition and muscle strength in elderly, as well as to identify the efficient dosages to reach these effects. METHODS This review included studies that evaluated muscle mass and muscle strength, associated or not with physical exercise and diet in elderly people. Only studies published from 2008 to 2019 were selected for analysis. RESULTS Six articles were included in the review. The used doses varied from 1.5 to 3 g. In 5 studies, HMB supplementation was associated with calcium; only 1 study did not use the oral administration route. Two studies used 4 g of maltodextrin as a vehicle; 1 used HMB with a hypercaloric and hyperproteic supplement; 1 associated HMB with lysine and arginine; and 1 with arginine and glutamine. Supplementation of 3 g of HMB has shown to be most beneficial in improving strength and body composition in people over 65 years, especially in bed rest and untrained conditions. CONCLUSION Our findings suggest that HMB has a positive effect on body composition and strength, especially in bedridden or sedentary elderly, due to its anticatabolic properties.