Muscle quality and metabolomics analysis of young and old subjects (1026.9)

Abstract

Sarcopenia, with declines in muscle mass and function, represents an independent risk factor for frailty, disability and mortality in older adults. Underlying changes are not clearly defined but may include muscle atrophy and myopathy. Contributing factors include declines in sex hormones, loss of protein synthesis capacity, neuromuscular integrity, lower physical activity, inflammation and oxidative stress. To understand the impact of aging on systemic metabolism, global metabolomic analysis of 10 serum samples/group were performed in young women (YW) (29.1 ± 4.2 y, 24.2 ± 2.7 BMI), older women (OW) (74.6 ± 6.4 y, 21.2± 2.5 BMI) and older men (75.2 ± 9.8 y, 24.5 ± 2.2 BMI). Fatty acid oxidation markers were higher in older subjects. Acylcarnitines (oleoyl‐, octanoyl‐ and acetyl‐) were elevated in OW compared to YW but did not differ between OW and men. Markers of renal function and steroid hormones followed similar patterns. Acetoacetate was higher in OW compared to older men and glycerol was elevated in OW compared to both groups. EPA, DPA, and DHA, were higher in older women compared to YW but did not differ from older men. Metabolites indicate a decline in renal function and steroid hormones in OW; however, indicators of elevated mitochondrial β‐oxidation were higher in older subjects. Ongoing analyses will evaluate the relationship between these metabolite changes to body composition and muscle performance.