Smoking modifies the effect of two independent SNPs rs5063 and rs198358 of NPPA on central obesity in the Chinese Han population.

Obesity is the third most risk factors of death in the middle-income and high-income countries. Whether DNA polymorphisms in CORIN and NPPA genes were associated with obesity, and if these associations could be modified by smoking in the Chinese Han population were unknown, hence a group of 1507 participants were recruited and genotyped for 12 tag single-nucleotide polymorphisms (SNPs) of CORIN and NPPA genes. Regression models were used to test the associations of SNPs with obesity. The potential SNP-smoking interactions were detected in regression models. NPPA SNPs rs5063 and rs198358 were associated with the body mass index (BMI) (P = 0.0053 and 0.0037, respectively). Rs198358 was associated with obesity in both univariate- and multivariable-adjusted analyses (P = 0.0138 and 0.0173, respectively). Rs5063 was associated with central obesity in both univariate- and multivariable-adjusted analyses (P = 0.0454 and 0.0361, respectively). Significant interactions between cigarette smoking and rs5063 and rs198358 were detected (P = 0.0019 and 0.0006, respectively). In subgroup analyses, rs5063 and rs198358 were associated with central obesity in smokers (P = 0.0081 and 0.0037, respectively). The results of our study demonstrated that the effect of NPPA SNPs rs5063 and rs198358 on central obesity might be modified by smoking in the Chinese Han population. Further studies are needed to confirm the associations and elucidate the underlying mechanisms.