Small-Scale Randomized Controlled Trial to Explore the Impact of β-Hydroxy-β-Methylbutyrate Plus Vitamin D3 on Skeletal Muscle Health in Middle Aged Women

• Published in: Nutrients Vol. 14; no. 21; p. 4674
• Main Authors: Fairfield, William D., Minton, Dennis M., Elliehausen, Christian J., Nichol, Alexander D., Cook, Taylor L., Rathmacher, John A., Pitchford, Lisa M., Paluska, Scott A., Kuchnia, Adam J., Allen, Jacob M., Konopka, Adam R.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 04.11.2022; MDPI
• Subjects: Adipose tissue; Aging; Alzheimer's disease; Arm; Body composition; Body fat; Cancer; Coronaviruses; COVID-19; Data analysis; Exercise; Fitness training programs; hypertrophy; intermuscular adipose tissue (IMAT); Metabolites; Middle age; Muscle function; Muscles; Musculoskeletal system; Older people; Physical fitness; Physical training; Placebos; Protein synthesis; Proteins; Questionnaires; resistance exercise; Sarcopenia; Sedentary behavior; Skeletal muscle; Thigh; Urine; Vitamin D; Vitamin D3; Womens health
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu14214674

β-Hydroxy-β-methylbutyrate (HMB), a leucine metabolite, can increase skeletal muscle size and function. However, HMB may be less effective at improving muscle function in people with insufficient Vitamin D3 (25-OH-D < 30 ng/mL) which is common in middle-aged and older adults. Therefore, we tested the hypothesis that combining HMB plus Vitamin D3 (HMB + D) supplementation would improve skeletal muscle size, composition, and function in middle-aged women. In a double-blinded fashion, women (53 ± 1 yrs, 26 ± 1 kg/m2, n = 43) were randomized to take placebo or HMB + D (3 g Calcium HMB + 2000 IU D per day) during 12 weeks of sedentary behavior (SED) or resistance exercise training (RET). On average, participants entered the study Vitamin D3 insufficient while HMB + D increased 25-OH-D to sufficient levels after 8 and 12 weeks. In SED, HMB + D prevented the loss of arm lean mass observed with placebo. HMB + D increased muscle volume and decreased intermuscular adipose tissue (IMAT) volume in the thigh compared to placebo but did not change muscle function. In RET, 12-weeks of HMB + D decreased IMAT compared to placebo but did not influence the increase in skeletal muscle volume or function. In summary, HMB + D decreased IMAT independent of exercise status and may prevent the loss or increase muscle size in a small cohort of sedentary middle-aged women. These results lend support to conduct a longer duration study with greater sample size to determine the validity of the observed positive effects of HMB + D on IMAT and skeletal muscle in a small cohort of middle-aged women.