Skeletal Muscle Composition and Glucose Levels in Children Who Are Overweight and Obese.

Abstract

Skeletal muscle is overlooked in the realm of insulin resistance in children who are overweight and obese despite the fact that it accounts for the most glucose disposal. Therefore, this study examined fasted glucose levels and muscle cross-sectional area and echo intensity (EI) via ultrasound images of the first dorsal interosseous, vastus lateralis, and rectus femoris in children who are normal weight and overweight and obese aged 8-10 years. In total, 13 males (age = 9.0 [0.7]y) and 7 females (age = 9.0 [0.8]y) volunteered for this study. Independent samples t tests and effect sizes (ESs) were used to examine potential differences in skeletal muscle composition and glucose concentrations. There were no significant differences between groups for glucose concentration (P = .07, ES = 0.86); however, the children who were overweight and obese had significantly greater EI (P < .01, ES = 0.98-1.63) for the first dorsal interosseous, vastus lateralis, and rectus femoris and lower cross-sectional area when normalized to EI when collapsed across muscles (P < .04, ES = 0.92). Glucose concentrations correlated with EI and cross-sectional area/EI for the vastus lateralis (r = .514 to -.593) and rectus femoris (r = .551 to -.513), but not the first dorsal interosseous. There is evidence that adiposity-related pathways leading to insulin resistance and skeletal muscle degradation are active in young children who are overweight and obese.