瘦素受体与载脂蛋白E基因型对肥胖儿童血脂的影响

Effects of Leptin Receptor and Apolipoprotein E Genotype on Blood Lipids in Obese Children

目的:探讨瘦素受体(LEP-R)外显子突变与载脂蛋白E(ApoE)基因型对肥胖患儿血脂的影响。方法:选择肥胖儿童(肥胖组)115例和非肥胖的健康儿童(健康组)84例为研究对象,空腹12 h后抽取患儿静脉血,测定血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平。采用聚合酶链式反应-限制性片段多态性(PCR-RFLP)方法及聚丙烯凝胶电泳分析LEP-R第20外显子的基因型及突变频率、ApoE基因型。结果:LEP-R基因共发现3种基因型,即G/G、G/A、A/A型。与健康组儿童相比,肥胖组患儿LEP-R基因第20外显子G A突变概率上升。与G/G基因型比较,A/A基因型肥胖儿童血清TG、LDL-C水平升高和HDL-C水平下降(P<0.05),G/A基因型肥胖儿童的HDL-C水平下降(P<0.05);肥胖组及健康组儿童ApoE等位基因以ε3型常见,肥胖组儿童ε4基因检出率高于健康组儿童(P<0.05)。与ApoE基因型ε3型肥胖儿童比较,ε2型肥胖儿童血清中的TC、LDL-C水平下降,HDL-C水平升高(P<0.05),ε4型肥胖儿童血清TC、TG、LDL-C水平升高(P<0.05);在G/A型肥胖儿童中,携带ε4型的肥胖儿童血清中TG、LDL-C水平高于非ε4型(P<0.05);在A/A型肥胖儿童中,携带ε4型ApoE基因的肥胖儿童血清中TC、TG、LDL-C水平高于非4型,血清HDL-C水平低于非ε4型(P<0.05)。结论:LEP-R基因型可影响肥胖儿童血脂水平,A/A型LPE-R基因儿童更易发生血脂异常。肥胖儿童ApoE基因型多变,ε4基因频率升高,且影响肥胖儿童脂类代谢,A/A型LEP-R基因同时携带ApoEε4等位基因的肥胖儿童更容易发生血脂异常。

Objective:To investigate the effects of leptin receptor(LEP-R) exon mutation and apolipoprotein E(ApoE) genotype on blood lipids in obese children.Methods:115 obese children(obese group) and 84 non-obese healthy children(healthy group) were selected as the study subjects.The venous blood of the children was drawn after 12 hours of fasting.The serum triglyceride(TG),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C) and low-density lipoprotein cholesterol(LDL-C) concentrations were measured.Polymerase chain reaction restriction fragment polymorphism(PCR-RFLP) method and polypropylene gel electrophoresis were used to analyze the genotype,mutation frequency and APOE genotype of exon 20 of LEP-R.Results:Three genotypes of LEP-R gene were found,namely G/G,G/A and A/A.Compared with healthy children,the probability of G A mutation in exon 20 of LEP-R gene increased in obese children.Compared with G/G genotype,serum TG and LDL-C levels were increased and HDL-C levels were decreased in obese children with A/A genotype(P<0.05).The HDL-C level in obese children with G/A genotype was decreased(P<0.05).Type ε3 of ApoE allele was common in children in obese group and healthy group.The detection rate of ε4 genes in children in obese group was higher than that in children in healthy group(P<0.05).Compared with type ε3 of ApoE genotype obese children,the serum TC and LDL-C levels in type ε2 obese children were decreased,and the HDL-C level was increased(P<0.05),and the serum TC,TG and LDL-C levels in type 4 obese children were increased(P<0.05).Among G/A obese children,the serum TG and LDL-C levels in carrying type ε4 obese children were higher than those non-type ε4(P<0.05).In type A/A obese children,the serum TC,TG and LDL-C levels in carrying type ε4 ApoE gene obese children were higher than those in non-type ε4 ApoE gene,and the serum HDL-C level was lower than that in non-type ε4 ApoE gene(P<0.05).Conclusions:LEP-R genotype can affect the blood lipid level of obese children,and children with type A/A LPE-R genotype are more prone to dyslipidemia.The ApoE genotype of obese children is variable,and the frequency of ε4 genes is increased,which affects the lipid metabolism of obese children.Obese children who carry ApoE 4 alleles in the type A/A LPE-R gene are more likely to have dyslipidemia.