中文摘要：

目的探讨黑皮素4受体基因（MC4R）rs12970134多态性、饮食、运动与儿童肥胖关系,为预防控制肥胖提供理论依据。方法对北京市东城区9所及海淀区5所学校2 030名7~18岁学生身体测量、饮食运动问卷调查及MC4R基因rs12970134多态性检测资料进行统计分析。结果 2 030名学生中rs12970134等位基因突变率（G〉A）为21.1%;GA/AA突变基因型频率在肥胖组与对照组间差异无统计学意义（P=0.222,OR=1.13,95%CI=0.93~1.36）;rs12970134基因GA/AA突变型与静态生活在肥胖发生中存在联合作用（P=0.015,OR=1.87,95%CI=1.13~3.31）。结论静态生活可能通过影响MC4R基因rs12970134多态性的作用,增加肥胖发生风险。

英文摘要：

Objective To study the relationship between children obesity and diet,physical activity and the rs12970134 polymorphism of melanocortin 4 receptor gene（MC4R） in Chinese children,and to provide evidence for prevention and control of obesity.Methods Totally 2 030 students aged 7 to 18 years were selected from 9 schools in Dongcheng and 5 schools in Haidian district,Beijing.Physical examination,questionnaire investigation and detection of the rs12970134 polymorphism were performed for all subjects.Results Mutation rate of the rs12970134 polymorphism was 21.1% in the subjects.No significant association was found in the mutation genotype between obese group and the control group（P=0.222,odds ratio=1.13,95% confidence interval：0.93-1.36）.The rs12970134 polymorphism and sedentary behavior had significant combined effect on obesity（OR=1.69,95%CI：1.13-3.31,P=0.015）.Conclusion Sedentary behavior might modify the effects of the MC4R rs12970134 variation on obesity in Chinese children.