Use of β-hydroxy-β-methylbutyrate to Counteract Muscle Loss in Men With Prostate Cancer on Androgen Ablation

It is well established that older patients experience age-related loss of muscle mass and function (sarcopenia), presumably due to an imbalance of protein synthesis versus protein breakdown. In addition, studies have shown that men who start on ADT experience increased muscle protein breakdown and decreased synthesis. β-hydroxy-β-methylbutyrate (HMB), a leucine metabolite, has been shown to slow protein breakdown. When HMB is given with arginine and lysine (which support protein synthesis) in randomized trials, researchers have shown that elderly men and women who receive this nutritional supplementation experience improvement in fat-free mass, strength, functionality and protein synthesis when compared with controls. In addition, patients with advanced cancer who experienced weight loss of at least 5% have also been shown to benefit from HMB, with supplementation resulting in a significant increase of fat-free mass when compared to controls. Thus, it seems reasonable that older men with prostate cancer starting on ADT who experience lean muscle loss as a result of aging and ADT, may achieve some benefit from supplementation with HMB as well. Use of HMB in men with prostate cancer has not been reported.