Evaluation of Genetic Susceptibility Loci for Obesity in Chinese Women

Recent genome-wide association (GWA) studies have identified 18 genetic loci for obesity. Using directly observed and imputed GWA genotyping data on approximately 5,000 Chinese women (1996-2007), the authors evaluated 17 single nucleotide polymorphisms (SNPs) that represent 17 distinct obesity loci. Two SNPs near the BAT2 and MC4R genes and 3 SNPs within the FTO, SEC16B, and SH2B1 genes were significantly associated with body mass index (weight (kg)/height (m)(2)), body weight, and the prevalence of obesity. The per-allele increase in body mass index ranged from 0.16 units (BAT2) to 0.38 units (SH2B1). Odds ratios for obesity ranged from 1.46 (95% confidence interval (CI): 1.12, 1.92) for BAT2 to 2.16 (95% CI: 1.39, 3.37) for MC4R. A genetic risk score calculated by summing the number of risk-increasing alleles that each woman carried at these 5 loci was significantly associated with the prevalence of obesity. Women carrying 5 or more risk alleles had a 3.13-fold (95% CI: 2.06, 4.77) higher prevalence of obesity than women carrying 1 or no risk alleles. Results from this study extend some previous GWA findings to Chinese women and show the need for additional studies to identify susceptibility loci in Chinese and other Asian populations.