胰岛素抵抗、胰岛素分泌功能对Ⅱ型糖尿病发生的影响

Effects of insulin resistance and insulin secretion on the development of type Ⅱ diabetes mellitus

目的探讨中国非糖尿病人群中胰岛素抵抗、胰岛素分泌功能对糖尿病发生的影响。方法以Ｈｏｍａ模型的胰岛素抵抗指数（ＩＲ）＝ＦＩＮＳ／２２５ｅ－ｌｎＦＰＧ（ＦＩＮＳ为空腹胰岛素，ＦＰＧ为空腹血糖）及β细胞功能指数（ＨＢＣＩ）＝ＦＩＮＳ×２０／（ＦＰＧ－３５），对４０９例非糖尿病者６年随访资料进行糖尿病发病危险因素的比例风险模型分析，再以胰岛素敏感性指数（ＩＡＩ）＝１／（ＦＰＧ×ＦＩＮＳ）、胰岛素分泌功能指数（ＩＳ）＝ＦＩＮＳ／ＦＰＧ这对更简单的指数进行同样分析，并与前者比较。结果以Ｈｏｍａ模型的ＩＲ、ＨＢＣＩ分析显示，排除口服葡萄糖耐量试验２小时血糖、体重指数因素影响后，ＩＲ与糖尿病正相关（Ｐ＜００５），ＨＢＣＩ与糖尿病负相关（Ｐ＜０．０１），生活方式干预有利于减少糖尿病发病危险。与以ＩＡＩ＝１／（ＦＩＮＳ×ＦＰＧ）、ＩＳ＝ＦＩＮＳ／ＦＰＧ分析结果相似。结论（１）胰岛素抵抗及胰岛素分泌功能差是Ⅱ型糖尿病发病危险因素；（２）仅涉及空腹血糖及空腹胰岛素的Ｈｏｍａ模型在流行病研究中可用于评价胰岛素抵抗及β细胞功能，ＩＡＩ＝１／（ＦＰＧ×ＦＩＮＳ）。

Objective To investigate the effects of insulin resistance and insulin secretion on the development of diabetes mellitus in Chinese nondiabetics. Methods 409 cases of non diabetic Chinese, including 125 with normal glucose tolerance (NGT) and 284 with impaired glucose tolerance (IGT) have been followed for six years for the incidence of diabetes since 1986. Subjects of IGT were involved in a life style intervention clinical trial. Insulin resistance index (IR)=FINS/22.5 e -lnFPG (FINS: fasting plasma insulin; FPG: fasting plasma glucose) and β cell function index (HBCI)=FINS×20/(FPG-3.5) in Homa model and the formulae insulin sensitivity index (IAI)=1/(FPG×FINS) and insulin secretion index (IS)=FINS/FPG were used as insulin resistance (or insulin sensitivity) and insulin secretion indices in the proportional hazard analysis . Results IR was positively and HBCI was negatively correlated with the development of non insulin dependent diabetes mellitus (NIDDM) ( P <0.05, P <0.01). Other risk factors of NIDDM include body mass index (BMI) and 2 hour plasma glucose (PG2h) at baseline. Life style intervention was demonstrated as a protective factor and the effect of combination of diet and exercise was likely superior to that of diet or exercise alone. The results did not change, if the more simple indices, IAI=1/(FPG×FINS) and IS=FINS/FPG, in stead of IR and HBCI suggested in Homa model were used. Conclusion (1) Both IR and HBCI are predictors of NIDDM in Chinese non-diabetic population even with life style intervention, which had a remarkable effect on reducing the incidence of NIDDM. (2) Homa model indices of IR and HBCI might be taken as the tools in prospective population-based study. However, the more simple indices, 1/(FPG×FINS) and FINS/FPG were likely to be better alternatives of Homa model indices practically.