肥胖儿童瘦素受体基因变异对脂质代谢及脂肪分布的影响

Effect of Variation of Leptin Receptor Gene on Lipid Metabolism and Fat Distribution of Children With Obesity

目的探讨瘦素受体(leptin receptor,LEPR)基因第20外显子变异对脂质代谢的影响。方法用聚合酶链式反应-限制性片断长度多态性(PCR-RFLP)法及聚丙烯酰胺凝胶电泳法分析120例单纯型肥胖儿童及120例健康儿童的LEPR基因的第20外显子基因变异频率,并测定血清中甘油三脂(TG)、总胆固醇(TC)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL),于相同条件下测身高、体重,按公式计算体重指数(BMI)、脂肪百分比(%fat)。结果共检出3种第20外显子的基因型,其酶切片段分别为:A/A型:201bp,75bp;A/G型:201bp,173bp,75bp,28bp;G/G型:173bp,75bp,28bp。肥胖儿童较健康儿童LEPR基因第3057位G→A突变频率增高(P<0.05)。纯合子A/A基因型的肥胖儿童其血清TG浓度、BMI、%fat均明显高于纯合子G/G基因型者(P<0.01),而血清HDL水平则明显低于后者(P<0.01),杂合子A/G型肥胖儿童,除其血清TG浓度高于纯合子G/G基因型者外(P<0.05),余各项指标均与另外两种基因型无显著性差异。结论单纯型肥胖儿童瘦素受体基因第20外显子存在基因多态性的变化,且这种变化明显影响肥胖儿童的脂质代谢及体脂分布。纯合子A/A基因型个体应提早注意饮食结构,避免由此而继发的各种疾病。

Objective To study the relationship between the variation of the 20 exon of leptin receptor （LEPR） and lipid metabolism of the children with obesity. Methods Polymerase chain reaction-restricted fragments length polymorphism （PCR-RFLP） and polyacrylamide gel electrophoresis were used to analyze the variation of the 20 exon of the LEPR gene of the obesity group （120 obese children） and the control group （120 healthy children）. Their serum triglyceride （TG）, total cholesterol （TC）, high density lipoprorein cholesterol （HDL-C）, height, weight measured and the body mass index （BMI）, fat percent （%fat） were calculated. Results 3 genotypes of the 20 exon of LEPR gene has been detected. Compared with the control group, the frequency of the gene variation at 3057 nucleotide G→A transversion is higher （P〈0. 05）. The concentration of the serum TG, the level of BMI and %fat of the obese children with A/A genotype were higher than that with the G/G genotype （P〈0. 01）, but the level of the serum HDL was lower （P〈0.01）. To the children with A/G genotype, only their TG level in serum are higher than that with the G/G genotype （P〈0.05）. Conclusion There is polymorphism at 20 exon LEPR gene in children with obesity, which may affect the lipid metabolism and the fat distribution. The obese children with A/A genotype should pay more attention to their diet to avoid some diseases followed obesity.