以(FINS×FPG)/(PG2h+PG1h-2FPG)评估胰岛β细胞分泌功能的可行性探讨

The possibility of (FINS×FPG)/(PG2h+PG1h-2FPG) being taken as an index of pancreatic β cell insulin secretion in a population based study

目的 探讨以一个修正的 β细胞胰岛素分泌指数 (MBCI) =(FINS×FPG) / (PG2h +PG1h- 2FPG) (FINS :空腹胰岛素 ;FPG :空腹血浆血糖 ;PG2h、PG1h :口服葡萄糖耐量试验 2h、1h血浆血糖 )评估 β细胞胰岛素分泌功能的可能性。方法 在 430例糖耐量正常 (NGT)和糖耐量低减 (IGT)人群中分析 (FINS×FPG) / (FG2h +PG1h - 2FPG)分辨血糖水平不同组间 β细胞功能差别的能力 ,并与应用胰岛素增值与血糖增值比值 (ΔI/ΔG)及HOMA胰岛素分泌指数 (HBCI) =2 0×FINS/ (FPG - 3 5 )的结果比较。结果 偏相关分析显示 ,在调整胰岛素敏感性影响后 ,在NGT人群HBCI与PG1h仅边缘相关(P =0 0 5 8) ,ΔI/ΔG与PG2h相关不显著 (P =0 2 3) ,而MBCI与PG1h、PG2h均显著相关 (P =0 0 0 0 1)。在含IGT与NGT的总组 ,MBCI比HBCI及ΔI/ΔG与PG1h及PG2h相关更密切 (与PG1h相关系数分别为 - 0 787,- 0 5 34及 - 0 5 0 7;与PG2h相关系数分别为 - 0 76 6 ,- 0 5 13及 - 0 396 )。MBCI及HBCI还能区别某些PG2h仅相差 1 10mmol/L的IGT亚组间 β细胞功能差别 ,ΔI/ΔG未能做出这种分辨。结论 (FINS×FPG) / (FG2h +PG1h - 2FPG)与HBCI和ΔI/ΔG都能分辨NGT和IGT组的 β细胞功能差别 。

Objective To investigate the possibility of using MBCI=(FINS×FPG)/(PG2h+PG1h-2FPG) (FINS: festing plasma insulin; FPG: festing plasma glucose; PG2h, PG1h: 2 h, 1 h plasma glucose) to evaluate β cell insulin secretion Methods (FINS×FPG)/(PG2h+PG1h-2FPG) was deduced from the physiologic concept that the increment of plasma glucose after glucose load negatively correlated to both insulin secretion of β cell and insulin sensitivity of the target tissue Then, it was used to evaluate the insulin secretion in 430 subjects of normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) in comparison with ΔI/ΔG and HOMA β cell insulin secretion index (HBCI)=20×FINS/(FPG-3 5) Results The insulin sensitivity adjusted partial correlation analysis showed: plasma glucose increment after glucose load was significantly correlated with MBCI, HBCI and ΔI/ΔG in the whole group including NGT and IGT( r =-0 787, r =-0 534, r = -0 507, P =0 000 1 for PG1h, r =-0 766, r =-0 513, r =-0 396, P =0 000 1 for PG2h respectively) The results were similar in IGT subjects ( r =-0 680, r =-0 417, r =-0 375, P =0 000 1 for PG1h, r =-0 446, r =-0 179, r =- 0 157, P = 0 000 1 for PG2h respectively) However in subjects with NGT, ΔI/ΔG was not correlated to PG2h significantly ( P =0 23), HBCI was only borderline correlated to PG1h( P =0 058) In contrast, MBCI was well correlated to both PG1h and PG2h ( P =0 000 1) This result indicated that MBCI correlated more closely to glucose increment in oral glucose tolerance test which was the most important outcome of insulin deficiency In addition, the least square means analysis demonstrated that MBCI (and HBCI to a less extent) could also distinguish the changes of insulin secretion in some IGT subgroups with 1 10 mmol/L PG2h difference Conclusion (FINS×FPG)/(PG2h+PG1h-2FPG), ΔI/ΔG and 20×FINS/ (FPG-3 5) could distinguish the remarkable difference of β cell insulin secretion such as between NGT and IGT However the (FINS×FPG)/(PG2h+PG1h-2FPG) was superior than the two other indices in the differentiation of less apparent changes of β cell function