The Relationship Between Intermuscular Fat and Physical Performance Is Moderated by Muscle Area in Older Adults
Year: 2020
Type: article
Abstract: BACKGROUND: Age-related deposition of fat in skeletal muscle is associated with functional limitations. Skeletal muscle fat may be present in people with preserved muscle mass or accompanied by muscle wasting. However, it is not clear if the association between muscle fat deposition and physical performance is moderated by muscle mass. OBJECTIVE: To determine whether the association between midthigh intermuscular fat and physical performance is moderated by muscle area. METHODS: We performed a cross-sectional analysis of the Health, Aging, and, Body Composition (ABC) study data collected in 2002-2003 (n = 1897, women: 52.2%). Midthigh muscle cross-sectional area (by computed tomography) and physical performance measures were compared across quartiles of intermuscular fat absolute area. Moderation analysis was performed to determine the conditional effect of intermuscular fat on physical performance as a function of muscle area. Conditional effects were evaluated at three levels of muscle area (mean and ± 1 standard deviation [SD]; 213.2 ± 53.2 cm2). RESULTS: Simple slope analysis showed that the negative association between intermuscular fat area (cm2) and leg strength (N·m) was of greater magnitude (beta coefficient [b], 95% confidence interval [CI] = -0.288 [-0.427, -0.148]) in participants with greater muscle area (ie, 1 SD above the mean) compared to those with lower muscle area (ie, at mean [b = -0.12 {-0.248, 0.008}] or 1 SD below the mean [b = 0.048 {-0.122, 0.217}]). Similarly, the negative association of intermuscular fat with 400-m walk speed (m/s) and chair stand (seconds) was greater in those with higher muscle areas (p < .001) compared to those with lower muscle areas. CONCLUSIONS: The association between higher intermuscular fat area and impaired physical function in aging is moderated by muscle area.
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: G100949702, DYNAMICS OF HEALTH,AGING, AND BODY COMPOSITION, Peripheral nerve decline: an underappreciated cause of injurious falls, DYNAMICS OF HEALTH, AGING, AND BODY COMPOSITION, HEALTH ABC--COORDINATING UNIT, G3375400798, Training in Molecular Epidemiology: Linking Genes to Physical Function in Older Adults, G5909482378, End of Life in the Very Old, G670738241, G861947890, G870807107, Pittsburgh Older Americans Independence Center, Training in the Epidemiology of Aging, G945304896
OpenAlex ID: W3040229410