中文摘要：

目的探讨摄食行为及能量代谢相关的重要蛋白质，黑皮素4受体（MC4R）基因变异与中国人肥胖的相关性。方法选取563例上海地区中国人，其中BMI≥30kg／m^2者258例，BMI〈23kg／m^2者305例，用DNA测序法检测MC4R基因nt-216C／T、nt-178A／C和Val103Ile变异。并测定所选人群身高、体重、腰围、臀围、股围、舒张压和收缩压。对所选人群进行口服糖耐量试验，测定空腹和糖负荷后120min血糖水平，并测定空腹血脂谱。以生物电阻抗法测定体脂含量。结果（1）中国人中nt-216C／T、nt-178A／C和Val103Ile变异频率均小于5％；（2）Logistic回归分析见到，MC4R基因Val103Ile变异是肥胖的独立相关因素（0R=0．414，P=0．040），Ile等位基因频率在肥胖患者中较低。（3）在正常体重组和肥胖组中分别比较VaL／Val纯合子与Ile携带者体脂参数、血糖、血脂、血压，差异无统计学意义。结论MC4R基因Val103Ile变异与中国人肥胖相关。

英文摘要：

Objective To investigate the association between the polymorphisms of melanocortin-4 receptor （MCAR） gene and obesity. Methods The genotypes of three polymorphisms, nt-216C/T, nt- 178A/C, and Val103Ile, were determined through DNA sequencing in 563 Chinese from Shanghai, including 258 individuals with body mass index （BMI） over 30 kg/m^2 and 305 individuals with BMI less than 23 kg/m^2. Height and body weight were measured to calculate BMI. Blood pressure was measured. Waistline, hipline, and femoral waist to calculate the waist-to-hip ratio and waist-to-femoral ratio were measured. Oral glucose tolerance test was conducted to detect the plasma glucose level during fasting condition and 120 minute after glucose loading. The levels of serum lipids, including total cholesterol, triglyceride, high-density hpoprutein cholesterol （HDL-C）, and low-density hpoprotein cholesterol. Results （1） The frequencies of nt-216C/T, nt-178A/C, and Val103Ile were all less than 5%. （2） Logistic regression showed that the Val103Ile variant was an independent risk factor for obesity （ OR = 0.414, P = 0.040）. The frequency of lie was less in the obese individuals compared with the controls. （3） In the controls and obese individuals, no association was detected between the genotypes and phenotypes. Conclusion Val103Ile variant of MCAR gene is associated with obesity in Chinese.