Study of 11 BMI-Associated Loci Identified in GWAS for Associations with Central Obesity in the Chinese Children

OBJECTIVE Recent genome-wide association studies have identified many single nucleotide polymorphisms (SNPs) associated with body mass index (BMI)/generalized obesity. In this study, we aimed to examine the associations of identified SNPs with risk of central obesity in a child population from China. METHODS We genotyped 11 SNPs (FTO rs9939609, MC4R rs17782313, GNPDA2 rs10938397, BDNF rs6265, FAIM2 rs7138803, NPC1 rs1805081, SEC16B rs10913469, SH2B1 rs4788102, PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479) in the Chinese children (N = 3502, age range 6-18 years) from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS). Based on the age- and sex- specific waist circumference (WC) standards generated in the BCAMS study, 1196 central obese cases and 2306 controls were identified. RESULTS Of 11 studied SNPs, four SNPs and genetic risk score (GRS) based on them were statistically significantly associated with central obesity by WC criteria (FTO rs9939609: OR = 1.29, 95%CI = 1.10-1.50, p = 0.001; MC4R rs17782313: OR = 1.27, 95%CI = 1.12-1.44, p = 1.32×10⁻⁴; GNPDA2 rs10938397: OR = 1.22, 95%CI = 1.09-1.37, p = 4.09×10⁻⁴; BDNF rs6265: OR = 1.20, 95%CI = 1.08-1.34, p = 8.86×10⁻⁴; GRS: OR = 1.25, 95%CI 1.16-1.34, p = 2.58×10⁻⁹) after adjustment for sex, age, pubertal stage, physical activity and family history of obesity. Similar observations were made using weight-to-height ratio (WHtR) criterion. However, other SNPs were not associated with central obesity by WC as well as WHtR criterion. CONCLUSIONS Our study replicates the statistically significant association of four SNPs (FTO rs9939609, MC4R rs17782313, GNPDA2 rs10938397, BDNF rs6265) with risk of central obesity in the Chinese children.