老年代谢综合征与非酒精性脂肪肝患者载脂蛋白E基因多态性检测的意义

Significance of apo E gene polymorphism in the elder's metabolic syndrome and nonalcoholic fatty liver

目的探讨老年代谢综合征(MS)与非酒精性脂肪肝(NAFL)的载脂蛋白E(apo E)基因多态性之间的关系及意义。方法本研究以60岁以上农村老年健康体检者筛检出的NAFL 126例、NAFL+MS 105例、非脂肪肝125例及体检正常老年者95名为研究对象,其血液应用特异引物扩增人DNA apo E基因265 bp片段和特异探针杂交后,通过分析熔解曲线检测基因突变点及多态性。酶联免疫吸附试验(ELISA)检测apo E、apo E4基因浓度,并进行血脂、血糖、尿素、酶类、体质指数和血压分析。结果NAFL组和NAFL+MS组以杂合子E2/3、E3/4基因型频率最高,分布频率分别为E2/3(36.5%、28.1%)、E3/4(27.2%、32.6%)、E3/3(32.3%、34.0%)、E2/4(2.4%、1.5%)、E4/4(0.8%、3.8%)、E2/2(0.8%、0.0%);NAFL+MS组E4/4频率显著高于对照组,apoE基因总浓度明显升高(P<0.05),E2/3、E3/4 2组血脂等生化指标和体质指数及血压均有不同程度增高,差异有显著性(P<0.05)。结论apo E基因多态性与老年NAFL和MS存在相关性,携带E3/4、E2/3型或E4/4型的个体存在,提示在决定个体老年MS合并NAFL遗传易感性方面有重要作用,apo E基因112位和158位的氨基酸残基发生相应的变化可引起不同程度的脂质代谢障碍。

Objective To investigate the relevance of the elder＇s metabolic syndrome（MS） and the apolipoprotein E（apo E） gene polymorphism in nonalcoholic fatty liver（NAFL）. Methods 126 cases NAFL,105 eases NAFL＋MS, 125 cases non-fatty liver and 95 healthy persons aged more than 60 years were selected from health examination. The 265 bp fiagment of apo E gene was genotyped by polymerase chain reahion （PCR） and then hybridized with the speciesspecific probe, melting curve was used to measure the genotyping of apo E point mutations and gene polymorphism. The expression of apo E and apo E4 was measured by enzyme-linked immunosorbent assay （ELISA） , and the serum lipid levels,glucose,urea nitrogen,enzyme, body mass index and blood pressure were determined, Results The most common allele was E2/3 in NAFL and NAFL ＋ MS, the fi＇equencies were： E2/3 （36. 5% , 28. 1% ） , E3/4 （27, 2% , 32.6% ）, E3/3 （32.3% ,34.0% ） ,E2/4 （2, 4%, 1.5% ）, E4/4 （0.8% ,3.8% ）, E2/2 （0.8% ,0.0% ） ; E4/4 in NAFL ＋ MS was higher than that of control group. The expression of apo E was up-regulated （ P 〈 0.05 ）. A slight increase of blood lipid,body mass index and blood pressure were observed, the difference was significant （P 〈 0. 05）. Conclusions There is positive relationship between the clder＇s MS and NAFL in apo E gene polymorphism, E3/4, E2/3 or E4/4 have an important role in the elder＇s MS with NAFL on genetic susceptibility. The amino acid residue changes of apo E point mutations 112,158 could cause metabolism disturbane.