Int J Obes (Lond), 2018; 42(4): 648-654, PMID: 29081501
The effects of muscle mass and muscle quality on cardio-metabolic risk in peripubertal girls: A longitudinal study from childhood to early adulthood.
Year: 2018
Cheng S, Wiklund P
Exercise, Health and Technology Center, Shanghai Jiao Tong University, Shanghai, China.
Abstract
BACKGROUND: Increased cardio-metabolic risk is well documented in children and adolescents with obesity and normal weight obesity. However, the associations of muscle mass and muscle quality with cardio-metabolic risk, independent of weight status from childhood to adulthood, has not been examined. METHODS: 236 girls were followed from pre-puberty to early adulthood. Fat mass and lean mass of the whole body were assessed by a dual-energy X-ray absorptiometry; muscle cross-sectional area, muscle density (skeletal muscle fat content) of the lower leg by the peripheral quantitative computerized tomography (pQCT) and blood glucose, insulin, triglycerides and HDL cholesterol by enzymatic photometric methods. Study participants were categorized based on BMI and percentage body fat (%BF) as normal weight obese (NWO=BMI; 18.5-24.9 with %BF >30) and normal weight lean (NWL=BMI; 18.5-24.9 with %BF <30). RESULTS: Girls with overweight and/or obesity from age of 11 to age 18 had greater lean mass and larger muscle cross-sectional area, but lower muscle density and skeletal muscle mass index than the normal weight girls (P<0.001 for all). Girls with normal-weight obesity had similar muscle cross-sectional area and muscle mass but lower muscle density and skeletal muscle index than their normal-weight lean peers from childhood to early adulthood (P<0.001 all). In all girls, muscle density and skeletal muscle index were inversely associated with cardio-metabolic risk score (r2=0.012, P<0.05 and r2=0.201, P<0.001, respectively). However, after adjusting for whole body fat mass or android abdominal fat mass, all associations disappeared. CONCLUSIONS: Skeletal muscle size and muscle mass are not associated with cardio-metabolic risk factors during pubertal growth after adjusting for measures of adiposity. Ectopic fat accumulation in the skeletal muscle and increased adiposity, particularly in the abdominal area in childhood, are significant contributors to increased cardio-metabolic risk in adulthood, irrespective of body weight status.International Journal of Obesity accepted article preview online, 30 October 2017. doi:10.1038/ijo.2017.267.GID: 4549; Last update: 06.11.2017
