肥胖儿童糖负荷后血糖和胰岛素分泌特点及胰岛 β 细胞功能预测分析

摘要： 目的 分析肥胖儿童糖负荷后血糖、 胰岛素分泌特点及胰岛素抵抗 （IR） 情况， 以预测评估胰岛 β 细胞功能状态。方法 将 635 例肥胖儿童按血糖水平分为血糖正常组 （NGT 组， 483 例）、 糖调节受损组 （IGR 组， 112 例） 和初发 2 型糖尿病组 （DM 组， 40 例）； 按 BMI 水平分为肥胖 1 组 （23 kg/m2 ≤BMI＜30 kg/m2 ， 393 例）， 肥胖 2 组 （BMI≥30 kg/m2 ， 242 例）。测定空腹及糖负荷后 0.5 h、 1 h、 2 h、 3 h 血糖 （FPG、 0.5 h-PG、 1 h-PG、 2 h-PG、 3 h-PG） 和胰岛素水平（FINS、 0.5 h-INS、 1 h-INS、 2 h-INS、 3 h-INS）， 并计算胰岛素抵抗指数 （HOMA-IR）、 总体胰岛素敏感指数 （WBISI）、胰岛细胞功能指数 （HOMA-β）、 早期胰岛素分泌指数 （ΔI30/ΔG30）、 胰岛素曲线下面积 （AUCI）。结果 IGR 组各时间点胰岛素水平均高于 NGT 组， DM 组在 0.5 h、 1 h 和 2 h 的胰岛素水平低于 IGR 组 （均 P＜0.05）。与 NGT 组比较， IGR 组 AUCI、 HOMA-IR 和 HOMA-β 升高， WBISI 和 ΔI30/ΔG30 降低 （均 P＜0.05）； DM 组 HOMA-IR 升高， WBISI、 HOMA-β 和 ΔI30/ΔG30 降低 （均 P＜0.05）； DM 组 AUCI、 HOMA-β 和 ΔI30/ΔG30 均低于 IGR 组 （均 P＜0.05）。肥胖 2 组 FINS、 AUCI、 HOMA-IR、 2 h-PG、 HOMA-β 均高于肥胖 1 组， WBISI 低于肥胖 1 组 （均 P＜0.05）； 2 组间 FPG 和 ΔI30/ΔG30 差异均无统计学意义。结论 肥胖儿童从 NGT、 IGR 到 DM 发展过程中， 存在胰岛素分泌高峰后延， IR 程度加重， 胰岛β 细胞功能代偿并最终减退。

Characteristics of plasma glucose and insulin secretion after a glucose load and prediction of islet beta cell function in obese children

Abstract: Objective To investigate the characteristics of plasma glucose, insulin secretion and changes of insulin resistance (IR) after a glucose load in obese children, and to predict islet β-cell function. Methods A total of 635 obese children were classified into normal glucose tolerance (NGT) group (n=483), impaired glucose regulation (IGR) group (n= 112) and type 2 diabetes mellitus (DM) group (n=40) based on their glucose levels. Subjects were also divided into G1 group (23 kg/m2 ≤BMI＜30 kg/m2 , n=393) and G2 group (BMI≥30 kg/m2 , n=242) based on their different BMI levels. Level of fast plasma glucose (FPG, 0.5 h-PG, 1 h-PG, 2 h-PG and 3 h-PG) and insulin (FINS, 0.5 h-INS, 1 h-INS, 2 h-INS and 3 h- INS) were measured 0 h, 0.5 h, 1 h, 2 h and 3 h after a glucose load. Insulin resistance index (HOMA-IR), whole body insulin sensitivity index (WBISI), function of pancreatic beta-cell (HOMA- β), first-phase insulin secretion index (ΔI30/ ΔG30) and area under curve of insulin (AUCI) were calculated and compared between groups. Results The value of insulin at each time point was significantly higher in IGR group than that of NGT group. The values of insulin at 0.5 h, 1 h, and 2 h were significantly lower in DM group than those of IGR group, respectively (all P＜0.05). Compared with NGT group, AUCI, HOMA- IR and HOMA- β increased, but WBISI and ΔI30/ΔG30 decreased in IGR group (all P＜0.05). HOMA- IR increased but WBISI, HOMA-β and ΔI30/ΔG30 decreased in DM group (all P＜0.05). Compared with IGR group, AUCI, HOMA-β and ΔI30/ΔG30 decreased in DM group (all P＜0.05). Values of FINS, AUCI, HOMA-IR, 2h-PG and HOMA-β were significantly higher in G2 group than those of G1 group, but WBISI decreased (all P＜0.05). There were no significant differences in FPG and ΔI30/ΔG30 between these two groups. Conclusion From NGT, IGR to DM, the peak of insulin secretion is postponed, insulin resistance is getting heavier and the compensation of insulin secretion after a glucose load is increased first and then decreased.