|摘要||目的 探讨血管紧张素转化酶(angiotensin converting enzyme,ACE)基因插入/缺失(insertion/deletion,I/D)多态性及胰岛素受体亚单位-1(insulin receptor substrate-1,IRS-1)基因Gly972Arg突变对出生体重的影响.方法 将入选296例新生儿分为两组,适于胎龄儿组222例,小于胎龄儿组74例,于生后3 d哺乳前检测血糖、胰岛素,计算HOMA-IR值比较两组的胰岛素敏感性;应用PCR-RFLP方法分析IRS-1基因Gly972Arg突变及ACE基因I/D多态性,比较各基因型组间出生体重、出生体重百分位.结果 小于胎龄儿组HOMA-IR值(Ln对数转换后)为0.217±0.367,高于适于胎龄儿组0.001±0.378(P<0.01).IRS-1基因突变组与野生型相比,出生体重较轻,分别为(2270.00±638.97)g及(2655.53±774.78)g,出生体重百分位较低,分别为(13.12±10.76)%及(39.87±30.18)%,差异均有统计学意义(P<0.05).ACE基因DD基因型出生体重百分位为(27.05±24.70)%,低于ID基因型(39.21±29.37)%及Ⅱ基因型(44.69±27.91)%,差异有统计学意义(P<0.05).同时具有ACE基因DD基因型及IRS-1基因突变者出生体重最低(2516.00±230.28)g,低于正常组(2919.87±717.04)g及具有一种基因多态性组(2572.44±724.20)g;其出生体重百分位也最低(18.00±14.89)%,低于正常组(44.97±27.07)%及具有一种基因多态性组(26.95±20.70)%,差异均有统计学意义(P<0.05).结论 IRS-1基因Gly972Arg突变及ACE基因I/D多态性可能对胎儿宫内发育和出生体重具有影响.
Objective To investigate the influence of angiotensin converting enzyme(ACE) gene insertion/deletion(I/D) polymorphism and insulin receptor substrate-1(IRS-1) gene Gly972Arg polymorphism on birthweight. Methods Totally,296 newborns were selected and divided into adequate-for-gestational-age(AGA) group (222 case) and smal-for-gestational-age(SGA) group(74 case).Serum glucose and insulin levels were examined on the 3rd day before feeding.Insulin sensitivity was calculated and compared.IRS-1 gene Gly972Arg polymorphism and ACE gene I/D polymorphism(202 cases) were analyzed using PCR-RFLP.Gestational age,birthweight and birthweight percentiles were compared between different genotype groups. Result The HOMA-IR level in SGA group was significantly higher than the AGA group(0.217±0.367 vs 0.001±0.378,P＜0.001).The frequency of IRS-1Gly972Arg mutation was higher in the SGA group than in the AGA group(10.81% vs 3.15%,P=0.009) and similar result was found in the frequency of Arg972 allele(5.41% vs 1.58%,P=0.010).The gestational age was almost the same between IRS1Gly972Arg mutation group and Gly972/Gly972 genotype group.However,the birthweight in the former group was lower than the latter[(2270.00±638.97)g vs (2655.53±774.78)g,P=0.001]The frequencies of ACE gene DD genotypes and D allele were higher in SGA group than AGA group (30.16% vs 14.39%,P=0.009;53.97% vs 38.85%,P=0.005).No significant difference was shown in the birthweight among DD,ID and Ⅱ genotype groups.The DD carriers have significantly lower birthweight percentile than ID and Ⅱ group[(27.05±24.70)% vs (39.21±29.37)%,P=0.019;and vs (44.69±27.91)%,P=0.002].Newborns with both DD and IRS-1GIy972Arg mutations had extremely lower birthweight than normal group and those with only one mutation [(2516.00±230.28)g vs (2919.87±717.04)g,P=0.002;and vs (2572.44±724.20)g,P=0.047]and had lower birthweight percentile than the above two groups[(18.00±14.89)% vs (44.97±27.07)%,P=0.002;and vs (26.95±20.70)%,P=0.011]. Conclusions IRS-lgene Gly972Arg mutation and ACE gene I/D polymorphism may influence intrauterine fetal growth and birthweitht.|