This is a controlled, open-label, parallel-group, randomized, investigator initiated study to evaluate the effectiveness of oral nutritional supplement containing β-hydroxy-β-methylbutyrate (Ensure® Plus Advance) on thigh muscle mass and physical performance in elderly subjects with pre-frail status. The study is planned to enroll a total of 70 elderly subjects with pre-frail status defined by Fried's criteria with modified cutoff values as suggested by Asian Working Group for Sarcopenia (AWGS) for Asian population. The subject to be enrolled will meet the phenotypic definition of pre-frail for one or two of five phenotypic criteria: weakness as measured by grip strength, slow walking speed, low level of physical activity, self-reported exhaustion, and unintentional weight loss.~After obtaining informed consent and the confirmation of eligibility, subjects will be randomized into the HMB or control group in a 1:1 ratio. All enrolled subjects will be under standard care, which is mainly dietary consultation for healthy aging by dietitians to assure sufficient dietary protein intake in all subjects. Subjects assigned to the HMB group will consume 2 bottles of Ensure® Plus Advance per day for 12 weeks additionally, while subjects assigned to the control group will not receive any placebo or active control.~In this study, subjects will be requested for a total of 4 visits at the clinical site, including screening visit, Visit 1 for randomization, Visit 2 at Week 6, and Visit 3 at Week 12 (end of study/EOS). The telephone visit will be scheduled at Week 3 and Week 9 to follow-up with subjects.~Thigh muscle mass of all subjects will be evaluated by MRI. The physical performance of subjects will be determined by short physical performance battery (SPPB) and handgrip strength. The nutrition status of subjects will be measured by MNA® -SF and nutrition biomarkers, including serum albumin, pre-albumin, 25-hydroxy-vitamin D, vitamin B12, and C-reactive protein (CRP). SF-36v2™ Health Survey will be used to evaluate the quality of life of subjects. The safety profile of Ensure® Plus Advance will be determined by monitoring the adverse event (AE/SAE) during the study period. Blood samples of each subject will be collected at Visits 1, 2 and 3 for analysis of nutrition biomarkers. There will be a total of approximately 30 mL of blood to be collected from each subject during the study period.
Primary objective:~To evaluate the effects of additional oral nutritional supplement containing β-hydroxy-β-methylbutyrate (HMB) on thigh muscle mass in elderly subjects with pre-frail status~Secondary objectives:~To evaluate the effects of additional oral nutritional supplement containing β-hydroxy-β-methylbutyrate on physical performance, nutrition status, and quality of life in elderly subjects with pre-frail status~To determine the safety profile of additional oral nutritional supplement containing β-hydroxy-β-methylbutyrate in elderly subjects with pre-frail status