J Gerontol A Biol Sci Med Sci. 2026 Feb 27:glag062. doi: 10.1093/gerona/glag062. Online ahead of print.
ABSTRACT
BACKGROUND: The INVEST in Bone Health Trial examined the effects of weight loss (WL), WL plus resistance training (WL+RT), or WL plus weighted vest use (WL+VEST) on musculoskeletal health. This secondary analysis evaluated changes in muscle area and density using computed tomography (CT) and lean and fat mass using dual-energy X-ray absorptiometry (DXA).
METHODS: 150 participants (50/group) were randomized to 12-months of WL, WL+RT, or WL+VEST, undergoing CT and DXA scans at baseline, six- and 12-months. DXA measured lean and fat mass, while CT assessed muscle and intermuscular adipose tissue (IMAT) cross-sectional area (CSA) and density. Mixed linear models evaluated changes and treatment effects, and partial Pearson’s correlations examined relationships between weight change and CT/DXA outcomes.
RESULTS: Participants (66.4±4.6 years,75% female,69% white) were living with overweight (14.7%) or obesity (85.3%). All groups achieved similar and significant weight loss (∼10%). At 12-months, WL+RT increased mid-thigh muscle CSA (0.5%, p < 0.05), improved muscle density (3.7-5.9%, p < 0.03), and reduced IMAT (20-22%, p < 0.05) and fat masses (22-26.8%, all p < 0.061). At the trunk, WL+VEST showed a trend toward muscle preservation and improved density (4.2%, p = 0.08) compared to WL, but had minimal impact on other measures. Differences between WL+VEST and WL were insignificant (all p > 0.05), but group comparisons showed improvements for WL+RT. Weight loss correlated with increased muscle density (r < 0, p < 0.001) but reduced muscle CSA and IMAT (r > 0, p < 0.001), indicating improved quality but reduced quantity.
CONCLUSION: Our findings underscore the significance of weight loss-associated muscle loss, highlighting progressive RT as a minimally effective preservation strategy.
PMID:41761582 | DOI:10.1093/gerona/glag062
