The Combined Use of Hydroxymethylbutyrate and Branched-Chain Amino Acids to Counteract Uremic Sarcopenia

Background: Hemodialysis (HD) patients frequently develop muscle wasting and chronic inflammation, conditions associated with functional decline and reduced quality of life (QoL). Nutritional strategies that provide targeted anabolic support without increasing nitrogen load may offer clinical benefits. The aim of this study was to evaluate the possible impact of a food for special medical purposes (FFSMP), composed of free-form branched-chain amino acids, β-hydroxy-β-methylbutyrate, and zinc, on muscle mass and strength, laboratory parameters, physical performance (PP), and QoL in HD patients. Methods: in this randomized double-blind crossover study, 24 adult HD patients received the FFSMP (10 g/day; two sachets) supplementation or placebo for 12 weeks, separated by an 8-week wash-out (protocol code RS 29.23). Measured outcomes included quadriceps rectus femoris thickness (QRFT) muscle, body composition analysis, inflammatory markers, oxidative stress indices, other routine biochemical parameters, PP, and QoL (SF-36 questionnaire). Results: FFSMP supplementation resulted in significant increases in QRFT and in fat-free mass percentage. Reductions in oxidative stress and inflammatory biomarkers were observed. Routine biochemical parameters remained stable, with the exception of a decrease in pre-dialysis urea. Functional performance measures did not differ between treatment periods. Improvements were noted in selected SF-36 domains, specifically energy/fatigue and general health. No major adverse events occurred during the study. Conclusions: In HD patients, this FFSMP produced favorable changes in markers of muscle mass and systemic inflammation without affecting short-term physical performance. These findings support the potential clinical utility of targeted amino acid supplementation in this patient population, highlighting the need for larger, longer-term trials.