Describe the characteristics of obesity phenotype in Chinese children, and to explore the associations of body fat distributions and distinct obesity phenotype.Design and Method:
Children aged 6–18 years were recruited from eight cities in China. Stratified cluster sampling method was used. Height, weight, waist circumference and blood pressure were measured. Fasting plasma glucose, serum high-density lipoprotein cholesterol and triglyceride were examined. Body fat distributions were estimated by whole-body DXA scans (Hologic Discovery-A fan beam densitometer). Obesity was diagnosed based on body mass index by cutoffs recommended by Working Group on Obesity in China (7–18 yrs) and the US 2000 CDC growth charts (6 yrs). Adjusted NCEP III metabolic syndrome criteria was used to estimate metabolic disorder. Combined obese and metabolic status, participants were classified into 4 obesity phenotypes: metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW). Children were divided into four groups according to visceral fat mass (VFM) and trunk fat mass (TFM) quartiles, separately.Results:
12599 children involved in this study, 8948 of them contained DXA body composition data. The overall prevalence of obesity is 12.5% (male vs. female: 16.7% vs. 8.2%). Rates of prevalence of MHO, MUO, MHNW, MUNW are 7.5%, 5.2%, 64.4%, 8.8% in the whole population. Stratified by age and gender, VFM and TFM are higher in MUO and MUNW groups than MHO and MHNW groups, and those whose VFM and TFM in the highest quartile are more likely to fall into MUO and MUNW groups among elder children (13–18 yrs), especially in boys.Conclusions:
Adiposity deposit in viscera and trunk are related to distinct metabolic phenotypes in elder but not younger children. The amount and duration of fat accumulation might contribute to metabolic disorder.