妊娠期糖代谢异常与血糖正常孕妇胰岛素抵抗及胰岛β细胞功能的比较

Comparison of insulin resistance and pancreatic β cell function between the pregnant women with normal and abnormal glucose metabolism

目的观察正常孕妇及糖代谢异常孕妇在妊娠早、中、晚期胰岛素抵抗及胰岛β细胞功能的变化规律，比较不同糖代谢状态相应孕期胰岛素抵抗及胰岛β细胞功能的差别，探讨妊娠期糖尿病（GDM）早期诊断的可行性。方法2009年2月至2010年3月在中山大学孙逸仙纪念医院进行早孕安胎、优生咨询及定期产检的507例孕妇，排除妊娠前患有糖尿病、甲状腺功能亢进症等内分泌疾病者，进行前瞻性研究。对受试者给予75g口服葡萄糖耐量试验（OGTr）及胰岛素释放试验，根据血糖是否异常分为GDM早孕组（58例），早孕对照组（72例），GDM中孕组（81例），中孕对照组（164例），GDM晚孕组（66例），晚孕对照组（66例）。分别比较各组稳态模型评估的胰岛素抵抗指数（HOMA-IR）、稳态模型评估的胰岛β细胞功能指数（HOMA-B）、血糖曲线下面积（AUCG）、胰岛素曲线下面积（AUCI）、早期胰岛素分泌指数（△I30／△G30）、混合胰岛素敏感度（ISIcomp）。结果（1）GDM早孕组AUCG、AUCI均高于早孕对照组，△I30／△G30及ISIcomp低于早孕对照组（P〈0．05），而HOMA—IR差异无统计学意义（P〉0．05）；GDM中孕组及GDM晚孕组HOMA-IR、AUCG均高于相应对照组，△I30／△G30及ISIcomp均低于相应对照组（P〈0．05），各组的HOMA—B差异均无统计学意义（P〉0．05）。（2）血糖及胰岛素释放曲线显示，早、中、晚孕正常对照组服糖后0．5h血糖水平达峰值，服糖后0．5—1h胰岛素水平达峰值，而GDM早、中、晚孕组服糖后1h血糖水平达峰值，服糖后2h血胰岛素水平达到峰值。结论早期妊娠与中、晚期妊娠诊断的GDM患者胰岛素抵抗均较相应孕期正常妇女增高，且OGTY后血糖及胰岛素峰值延迟，GDM患者妊娠早期即出现了胰岛素早期分泌功能受损。对高危人群在早期妊娠行OGTT可及早发现糖代谢异常。

Objective To observe and compare the variation of insulin resistance and pancreatic β-cell function in pregnant women with abnormal and normal glucose metabolism during the first, second, and third trimesters, and to explore the feasibility of early diagnosis of gestational diabetes mellitus （ GDM ）. Methods This is a prospective study. 507 pregnant women with regular antenatal care from February 2009 to March 2010 were included in the study. Based on the results of oral glucose tolerance test, the patients with GDM consisted of 58, 86, and 66 subjects respectively in the first, second, and third trimesters. The control group included 72, 164, and 66 subjects respectively in the first, second, and third trimesters. Homeostasis model assessment insulin resistance index（ HOMA- IR）, homeostasis model assessment β-cell function （ HOMA-β）, area under curve of glucose （ AUCG）, area under curve of insulin （ AUCI）, 30-minute insulin increase to 30-minute glucose increase （ △I30/△G30 ）, and insulin sensitivity index composite（ISIcomp） were calculated for the evaluation of insulin resistance and pancreatic β-cell function. Results （ 1 ） AUCG and AUCI in the GDM group were statistically higher than those in control group while △I30/△G3oand ISIcomp in the GDM group were statistically lower than those in the control group during the first trimester（ P〈0. 05 ）, but HOMA-IR showed no statistically significant difference between two groups. In the GDM groups HOMA-IR, AUCG, and AUCI were statistically higher, whereas AI30/AG30 and ISIcomp were statistically lower than those in the control groups during the second and third trimesters （P 〈 O. 05 ）. HOMA-13 showed no statistically significant differences between the GDM groups and control groups during 3 trimesters. （ 2 ） During the first, second, and third trimesters, blood glucose reached its peak by 0. 5 h in the oral glucose tolerance test, and insulin reached its peak by 0. 5-1 h in the control groups ; while in the GDM groups the respective figures were 1 h and 2 h. Conclusions The insulin resistance in GDM patients diagnosed during the first, second, and third trimesters was higher than in pregnant women with normal glucose metabolism, and the peaks of blood glucose and insulin reached in oral glucose tolerance test were respectively delayed. The impaired pancreatic △-cell insulin secretion in GDM patients was present from early pregnancy. Thus for high-risk groups, oral glucose tolerance test during early pregnancy will be helpful for screening abnormal glucose metabolism.