Effects of Gene-Environment Interaction on Obesity among Chinese Adults Born in the Early 1960s

The prevalence of obesity has been increasing sharply and has become a serious public health problem worldwide. Gene–environment interaction in obesity is a relatively new field, and little is known about it in Chinese adults. This study aimed to provide the effects of gene–environment interaction on obesity among Chinese adults. A stratified multistage cluster sampling method was conducted to recruit participants from 150 surveillance sites. Subjects born in 1960, 1961 and 1963 were selected. An exploratory factor analysis was used to classify the environmental factors. The interaction of single nucleotide polymorphisms (SNPs) and environmental factors on body mass index (BMI) and waist circumference were analyzed using a general linear model. A multiple logistic regression model combined with an additive model was performed to analyze the interaction between SNPs and environmental factors in obesity and central obesity. A total of 2216 subjects were included in the study (mean age, 49.7 years; male, 39.7%, female, 60.3%). Engaging in physical activity (PA) could reduce the effect of MC4R rs12970134 on BMI (β = −0.16kg/m(2), p = 0.030), and also reduce the effect of TRHR rs7832552 and BCL2 rs12454712 on waist circumference (WC). Sedentary behaviors increased the effects of SNPs on BMI and WC, and simultaneously increased the effects of FTO rs9939609 and FTO rs8050136 on obesity and central obesity. A higher socioeconomic status aggravated the influence of SNPs (including FTO rs9939609, BNDF rs11030104, etc.) on BMI and WC, and aggravated the influence of SEC16B rs574367 on central obesity. The MC4R rs12970134 association with BMI and the FTO rs8050136 association with central obesity appeared to be more pronounced with higher energy intake (β = 0.140 kg/m(2), p = 0.049; OR = 1.77, p = 0.004, respectively). Engaging in PA could reduce the effects of SNPs on BMI and WC; nevertheless, a higher socioeconomic status, higher dietary energy intake and sedentary behaviors accentuated the influences of SNPs on BMI, WC, obesity and central obesity. Preventative measures for obesity should consider addressing the gene–environment interaction.