Effect of β-hydroxy-β-methylbutyrate (HMB) on lean body mass during 10 days of bed rest in older adults

Clin Nutr. 2013 Oct;32(5):704-12. doi: 10.1016/j.clnu.2013.02.011. Epub 2013 Mar 4.


Background: Loss of muscle mass due to prolonged bed rest decreases functional capacity and increases hospital morbidity and mortality in older adults.

Objective: To determine if HMB, a leucine metabolite, is capable of attenuating muscle decline in healthy older adults during complete bed rest.

Design: A randomized, controlled, double-blinded, parallel-group design study was carried out in 24 healthy (SPPB ≥ 9) older adult subjects (20 women, 4 men), confined to complete bed rest for ten days, followed by resistance training rehabilitation for eight weeks. Subjects in the experimental group were treated with HMB (calcium salt, 1.5 g twice daily - total 3 g/day). Control subjects were treated with an inactive placebo powder. Treatments were provided starting 5 days prior to bed rest till the end rehabilitation phase. DXA was used to measure body composition.

Results: Nineteen eligible older adults (BMI: 21-33; age: 60-76 year) were evaluable at the end of the bed rest period (Control n = 8; Ca-HMB n = 11). Bed rest caused a significant decrease in total lean body mass (LBM) (2.05 ± 0.66 kg; p = 0.02, paired t-test) in the Control group. With the exclusion of one subject, treatment with HMB prevented the decline in LBM over bed rest -0.17 ± 0.19 kg; p = 0.23, paired t-test). There was a statistically significant difference between treatment groups for change in LBM over bed rest (p = 0.02, ANOVA). Sub-analysis on female subjects (Control = 7, HMB = 8) also revealed a significant difference in change in LBM over bed rest between treatment groups (p = 0.04, ANOVA). However, differences in function parameters could not be observed, probably due to the sample size of the study.

Conclusions: In healthy older adults, HMB supplementation preserves muscle mass during 10 days of bed rest. These results need to be confirmed in a larger trial.

Trial registration: ClinicalTrials.gov NCT00945581.

Keywords: Beta-hydroxy-beta-methylbutyrate; Body composition; HMB; LBM; Lean body mass; Muscle; Protein synthesis; SPPB; Short Physical Performance Battery score.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Aged
  • Aging*
  • Bed Rest / adverse effects*
  • Body Composition
  • Dietary Supplements* / adverse effects
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Muscle Development*
  • Muscle Proteins / biosynthesis
  • Muscle Proteins / metabolism
  • Muscle Strength
  • Muscle, Skeletal / diagnostic imaging
  • Muscle, Skeletal / growth & development*
  • Muscle, Skeletal / metabolism
  • Musculoskeletal Physiological Phenomena
  • Resistance Training
  • Sarcopenia / etiology
  • Sarcopenia / metabolism
  • Sarcopenia / prevention & control*
  • Sarcopenia / rehabilitation
  • Valerates / adverse effects
  • Valerates / therapeutic use*
  • Whole Body Imaging


  • Muscle Proteins
  • Valerates
  • beta-hydroxyisovaleric acid

Associated data

  • ClinicalTrials.gov/NCT00945581