Elastic-band Resistance Exercise or Vibration Treatment With Hydroxymethylbutyrate (HMB) Supplement for Sarcopenic Older People

Sarcopenia is a geriatric syndrome characterised by the progressive loss of skeletal muscle mass and function with a risk of adverse outcomes. In Hong Kong, the prevalence of sarcopenia in community-dwelling older people was 9%. According to a meta-analysis on the effect of sarcopenia on health outcomes in older people, sarcopenia significantly increased hazard ratios of falling by 3.23×, functional decline by 3.03× and fracture risk by up to 3.75×, thus making sarcopenia a major risk factor for fragility fractures. Elastic-band exercise alone was shown to enhance skeletal muscle mass, performance and gait speed. Low-magnitude high-frequency vibration (LMHFV) was shown to be effective in enhancing muscle strength, balancing ability and reducing fall risk. HMB supplementation is advantageous due to its simplicity in administration and found to be effective in maintaining total lean mass, appendicular lean mass, leg and arm lean masses. The objective of this study is to evaluate the effectiveness of elastic-band exercise or vibration treatment in combination with HMB supplementation on the control of sarcopenia by a single-blinded randomized controlled study. Community-dwelling older people failing the sarcopenia screening according to the Asian Working Group on Sarcopenia (AWGS) will be recruited and randomized to (1) control, (2) Exercise + HMB or (3) LMHFV + HMB group by envelope drawing of computer-generated random numbers. Control group will be given promotional materials of sarcopenia and will not receive any intervention. The Exercise + HMB group will be instructed to take a thirty-minute home-based elastic band exercise practiced for 30 mins per day, 3 times per week for 3 months. The LMHFV + HMB group will be assigned to participating community centres and receive vibration treatment at 35Hz, 0.3g (peak to peak magnitude), displacement of \<0.1mm, for 20 min/day, at least 3 days/week for 3 months. Both HMB treatment groups will given 3.0 g/day for 3 months. Outcome assessments will be performed at baseline and end-point of 3 months. Outcome assessor and statistician will be blinded to group allocation. Muscle strength in the lower extremity will be the primary outcome. Muscle strength in the upper extremity, gait speed, muscle mass (based on AWGS definition), functional performance in terms of balancing ability and time-up-and-go test, quality of life by short-form 36 will be taken as secondary outcomes.