title: Dietary treatment of rheumatoid cachexia with beta-hydroxy-beta-methylbutyrate, glutamine and arginine: a randomised controlled trial.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA) is complicated by cytokine-driven alterations in protein and energy metabolism and consequent muscle wasting (cachexia). The aim of this randomised controlled trial was to investigate the efficacy of a mixture of beta-hydroxy-beta-methylbutyrate, glutamine and arginine (HMB/GLN/ARG) as nutritional treatment for rheumatoid cachexia.
  
  
  METHODS
  Forty RA patients supplemented their diet with either HMB/GLN/ARG or a nitrogen (7.19 g/day) and calorie (180 kcal/day) balanced mixture of alanine, glutamic acid, glycine, and serine (placebo) for 12 weeks. Body composition and other outcomes were assessed at baseline and follow-up, and analysed by mixed ANOVA.
  
  
  RESULTS
  Dietary supplementation with HMB/GLN/ARG was not superior to placebo in the treatment of rheumatoid cachexia (groupxtime interactions P>0.05 for all outcomes). Both amino acid mixtures significantly increased (main effect of time) fat-free mass (727+/-1186 g, P<0.01), total body protein (719+/-1703 g, P=0.02), arms (112+/-183 g, P<0.01) and legs (283+/-534 g, P<0.01) lean mass, and some measures of physical function. No significant adverse event occurred during the study, but patients in the HMB/GLN/ARG group reported fewer gastrointestinal complaints compared to placebo.
  
  
  CONCLUSIONS
  Dietary supplementation with HMB/GLN/ARG is better tolerated but not more effective in reversing cachexia in RA patients compared to the mixture of other non-essential amino acids used as placebo. Further controlled studies are necessary to confirm the beneficial anabolic and functional effects of increased nitrogen intake in this population.
authors.affiliation: School of Sport, Health and Exercise Sciences, University of Wales-Bangor, George Building, Holyhead Road, Bangor, Gwynedd LL57 2PX, UK. s.m.marcora@bangor.ac.uk
authors.forename: Samuele
authors.initials: S
authors.lastname: Marcora
authors.forename: Andrew
authors.initials: A
authors.lastname: Lemmey
authors.forename: Peter
authors.initials: P
authors.lastname: Maddison
mesh_terms: D001120:Arginine / Q000008:administration & dosage*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000378:metabolism* / Q000523:psychology; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D002100:Cachexia / Q000178:diet therapy* / Q000209:etiology / Q000523:psychology; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005973:Glutamine / Q000008:administration & dosage*; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D014631:Valerates / Q000008:administration & dosage*
chemical_list: D014631:Valerates; D005973:Glutamine; C004961:beta-hydroxyisovaleric acid; D001120:Arginine