Resistance Exercise Program and Branched Chain Amino Acid Supplementation in Heart Failure Patients

Overview

Heart Failure (HF) is a complex syndrome which can include the physiological, neural hormonal and metabolic complications known as "Cardiac Cachexia" (CC). In the development of CC there is a release of catabolic cytokines (Tumor Necrosis Factor-α, interleukins 1 and 6)that cause a decrease of fat free mass and fat mass. These changes in body composition might be reversed with a therapeutic combination of resistance exercise and branched chain amino acid supplementation (BCAA). Thus the purpose of this study is evaluate changes in body composition after a resistance exercise program and BCAA supplementation in patients with HF.

Heart failure (HF) is a complex syndrome which results from structural and/or functional alterations that limit the ability to respond to physiological demands(1,2).These abnormalities involve metabolic and neuro-hormonal factors such as tumor necrosis factor-α (TNF-α), one of the most important catabolic cytokines related with changes in body composition, interleukin 1 (IL-1), IL-6, interferon Y, and transmission growth factor β (3-9), which produce catabolic and anabolic imbalance and promote loss of fat free mass (FFM) with or without loss of fat mass (FM) in patients with HF. This syndrome is called "Cardiac Cachexia" (CC) (10). Signs and symptoms such as fatigue, anorexia and decreased muscle strength reflect altered body composition (9, 10). There are two possible ways to counteract these catabolic factors and restore body compartments. In one of them, protein supplementation promotes protein synthesis and inhibits proteolysis (3,11,12); in the other resistance exercise (RE) increases muscle mass and muscle strength, maintaining heart rate (13,14). Previous studies report the association of protein supplementation (15-17) and exercise (18-23) with changes in muscle strength in some cases and exercise capacity in HF patients. However, these therapies were not combined, and the studies did not provide enough information about changes in body composition. Based on these reports, our hypothesis is that the combination of RE and protein supplementation in form of branched chain amino acids (BCAA) might have an anabolic effect in patients with HF since the supplementation of BCAA could be helpful as "fuel" during the exercise and maintain the muscle mass metabolism (24).