Preserving the Metabolic Engine: HMB Supplementation to Combat Iatrogenic Sarcopenia and Metabolic Adaptation in Older Adults Initiating Semaglutide Therapy
Vanderbilt University Medical Center
Summary
This randomized, double-blind, placebo-controlled trial will evaluate whether daily calcium beta-hydroxy-beta-methylbutyrate (calcium-HMB) plus vitamin D3 preserves muscle mass, physical function, and resting metabolism in adults aged 65 to 85 years with type 2 diabetes who are newly starting semaglutide as part of usual clinical care. Participants will receive calcium-HMB plus vitamin D3 or matching placebo for approximately 6 months. The primary outcome is change in appendicular lean mass measured by dual-energy X-ray absorptiometry from baseline to month 6. Secondary assessments include body composition, muscle strength, physical performance, gait, physical activity, resting metabolic rate, metabolic measures, and whole-body quantitative computed tomography. An optional mechanistic substudy of up to 36 participants will include D3-creatine dilution, nonradioactive stable isotope infusions, repeated blood sampling, a standardized meal, breath sampling, and vastus lateralis muscle biopsies at baseline and month 6.
Description
Semaglutide treatment can produce substantial weight loss and improve glycemic control, but some weight loss may be accompanied by loss of lean tissue and skeletal muscle. Older adults with type 2 diabetes may be particularly vulnerable to loss of muscle mass, strength, mobility, and physical independence. Metabolic adaptation, defined as a reduction in resting metabolic rate beyond that expected from changes in body composition, may also occur during rapid weight loss. Calcium-HMB is a leucine metabolite with anabolic and anti-catabolic properties. This study will test whether supplementatio…