正常糖耐量者口服葡萄糖-胰岛素释放试验的胰岛素分泌曲线特点的研究

目的研究口服葡萄糖一胰岛素释放试验（OGIRT）的胰岛素（Ins）分泌曲线特点，初步探讨适用于I临床评价个体胰岛素敏感性和8细胞分泌功能的方法。方法对12例正常糖耐量者行OGIRT和静脉糖耐量试验（IVGTT），观察OGIRT、IVGTT血浆Ins分泌峰值时间分布频数，分析胰岛素敏感性和B细胞功能各指标相关指数。结果OGIRT血浆Ins分泌高峰出现于35-45min，无明显第二分泌峰。经多因素线性回归分析表明20、30、35minIns增值与葡萄糖增值的比值（ΔI20／ΔG20、ΔI30／ΔG30、ΔI35／ΔG35）与第一相（1PH）胰岛素分泌、葡萄糖及胰岛素曲线下面积比值（SGI）、胰岛素作用指数（IAI）、HOMA—IR、胰岛素分泌指数均不相关（P〉0．05），ΔI40／ΔG40与SGI、IAI、HOMA-IR显著相关（P均〈0．01）。结论OGIRT可能不能反映1PH；OGIRTΔI40／ΔG40比I20／ΔG20、△I30／ΔG30能更好地评估β细胞功能。

Investigation of insulin secretion curve during oral glucose insulin releasing test in subjects with normal glucose tolerance

Objective To observe the characteristics of the insulin （Ins） secretion curve in oral glucose insulin-releasing test （OGIRT）and to explore the applicable methods for clinical evaluation of individual insulin sensitivity and β-cell function. Methods OGIRT and intravenous glucose tolerance test （IVGTT） were carried out on 12 subjects with normal glucose tolerance（NGT）. Frequency distribution of the peak secretion time of plasma insulin in these two tests was observed, and relevant indices of insulin sensitivity and β-cell function were analyzed. Results The peak secretion time of plasma insulin was between 35 and 45 minutes in OGIRT, without obvious second peak. Multivariate linear regression analysis showed no association of the INS to glucose increment ratio at 20, 30 and 35 minutes （ΔI20/ΔG20,ΔI30/ ΔG30, ΔI35/ΔG35 ） with early time insulin secretion （IPH）, glucose to Ins ratio of area-under-curve （SGI）, INS sensitivity index （IAI）, HOMA-IR, or INS secretion index （MBCI） （all P〉0.05）. But ΔI10/ΔG10 was significantly associated with SGI, IAI and HOMA-IR （r= -0. 527 ,P= 0. 005 ; r=0. 406, P= 0. 015 ; r =0. 410,P=0. 015 respectively）. Conclusions The OGIRT may not reflect 1PH insulin secretion. In OGIRT, ΔI40/ΔG40 may be a better reflection of β-cell function than I20/ΔG20 or ΔI30/ΔG30. The results need further confirmation.