EFFECT OF ß-HYDROXY-ß-METHYLBUTYRATE (HMB) ON MUSCLE STRENGTH IN OLDER ADULTS WITH LOW PHYSICAL FUNCTION

Objectives: To evaluate the effects of β-hydroxy-β-methylbutyrate (HMB) on muscle strength, physical performance, and muscle mass without additional exercise training in older adults with low physical function. Design: Randomized, controlled trial (Open-label study). Setting: Outpatients. Participants: 34 senior outpatients with low physical function who do not exercise regularly. Intervention: 2.4 g of HMB (3.0 g of calcium β-hydroxy-β-methylbutyrate [CaHMB]) per day was given for 60 days, and subjects in the control group were asked to engage in daily activities as normal. Measurements: Weakness or low function was defined by the Asian Working Group for Sarcopenia criteria, then the participants were assigned to the HMB group or the control group. All participants underwent several evaluations such as grip strength, the timed up and go test, the 5-times chair stand test (5CS), and skeletal muscle mass index by the bioimpedance method at baseline and at the end of intervention or control period. Results: An intragroup comparison of pre- to post-treatment values showed significant improvement in grip strength and the 5CS in the HMB group (grip strength: HMB, 16.6±6.1 kg to 18.2±6.4 kg, P=.001; control, 16.5±4.3 kg to 16.7±4.7 kg, P=.729; 5CS: HMB, 11.0 [8.8-13.0] s to 10.1 [8.5-12.6] s, P=.011; control, 11.1 [8.6-13.8] s to 10.0 [8.8-11.3] s, P=.246). Two-way repeated measures analysis of variance (ANOVA) used to compare the HMB and control groups showed a significant improvement in grip strength in the HMB group compared with the control group (P=.029). Conclusion: A supplementation of HMB without additional exercise may improve muscle strength in older patients with low muscle strength.