Resistance Exercise or Vibration With HMB for Sarcopenia

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.

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 fracture.

A recent study reported a randomized controlled trial (RCT) of 3-month intervention of elastic-band exercise alone has shown significant enhancement in skeletal muscle mass by a 0.7 kg gain and a better performance demonstrated by 0.14 m/s faster gait speed. This project targets to investigate the application of elastic-band exercise for older people to carry out at home for sarcopenia intervention.

Low-magnitude high-frequency vibration (LMHFV) has previously shown to be effective in enhancing muscle strength, balancing ability and reducing fall risk in a RCT involving 710 subjects. Community-dwelling older people treated at 35 Hz, 0.3 g and 20 minutes per day for 18-months showed reduced hazard ratio for fall or fracture (HR=0.56, 95% CI at 0.40-0.78, p=0.001), 2.46 kg increase in quadriceps strength (95% CI at 1.70-3.22, p\<0.001) and overall statistically significant improvements in balancing ability.

HMB supplementation is advantageous due to its simplicity in administration compared to various other schemes. In a RCT on the efficacy of HMB supplementation on 10-day bed-rested older adults aged 60-76, 3.0-g/day was found to be effective in maintaining total lean mass, appendicular lean mass, leg and arm lean masses with significant differences.

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 the 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.

Eligibility Criteria:
Inclusion Criteria:

* 65 years old or above
* failing the sarcopenia screening based on the AWGS definition:

  1. hand-grip strength (male at \<26 kg, female at \<18kg),
  2. gait speed test (\<0.8m/s), and/or height-adjusted skeletal muscle mass by bio-impedance analysis (BIA, male at \<7kg/m\^2 and female at \<5.4kg/m\^2) defined by appendicular skeletal muscle mass/height\^2.

Exclusion Criteria:

* pathological bone diseases
* chronic inflammatory conditions known to affect muscle metabolism; including diabetes, rheumatoid arthritis
* neurological conditions affecting normal gait
* dependent ambulatory capability
* subjects taking regular guided exercise programmes of more than three times per week
* subjects with cardiovascular concern such as with pace-maker in-situ or malignancy
* chair-bound or bed-bound subjects
* recovering from fractures/surgeries or with implants (affecting DXA scan)