胰岛素抵抗是糖耐量正常人群糖耐量恶化的最重要危险因素

Insulin resistance is the most important risk factor of deteriorating glucose tolerance in subjects with normal glucose tolerance

目的 探讨胰岛素抵抗和胰岛素分泌对糖耐量正常人群糖耐量恶化的影响。方法 以口服葡萄糖耐量试验 (OGTT)做人群普查 ,确定糖耐量正常者 (NGT)〔空腹血糖 (FPG) <5 .8mmol/L及 2小时血糖 (PG2h) <6 .7mmol/L〕12 5例 ,测定血浆胰岛素。 6年后随访再以OGTT确定该人群糖耐量状态 ,以稳态模型 (HomaModel)公式评估胰岛素抵抗 (IR)、胰岛素分泌功能 (IS) ,并分析其对糖耐量恶化的影响。结果 12 5例糖耐量正常人中 ,6年后 2 3例糖耐量恶化〔IGT 2 0例 ,糖尿病(DM) 3例〕。糖耐量恶化者初访时FPG、PG2h与糖耐量仍正常者无明显差别 ,但前者 1小时血糖(PG1h)、1小时胰岛素 (INS1h)均较后者高 (P <0 .0 5 ) ,且前者较肥胖 (P <0 .0 5 )及胰岛素敏感性更差 (P <0 .0 5 )。按胰岛素敏感性三分变量分组 ,胰岛素敏感性最差组的糖耐量恶化率为胰岛素敏感组的 3倍 (34.2 %比 11.9%和 9.5 % ,P <0 .0 5 )。Logistic回归结果显示初访时的胰岛素敏感性与糖耐量恶化显著负相关 ,而年龄、性别、PG2h、体重指数 (BMI)及IS均与糖耐量恶化相关不显著。

Objective To investigate the effect of insulin resistance and insulin secretion on the deteriorating glucose tolerance in normal glucose tolerance (NGT) subjects. Methods 125 subjects of NGT 〔fasting plasma glucose (FPG)<5.8mmol/L and 2h plasma glucose (PG2h)<6.7mmol/L〕 were identified by standard oral glucose tolerance test (OGTT) in a survey on diabetes. Their plasma insulin was measured at baseline. After a 6 year follow up OGTT was repeated. Baseline insulin resistance and insulin secretion (IS) were assessed by Homa Model in order to investigate the influence of these two factors on the deteriorating glucose tolerance in subjects with NGT. Results 23 out of 125 subjects with NGT, deteriorating to impaired glucose tolerance (IGT) (20 cases) and diabetes mellitus (DM) (3 cases), appeared after six years. FPG and PG2h at baseline were not different between subjects who became IGT (or DM) and who remained NGT. However, the former group had higher 1h plasma glucose (PG1h), 1h insulin (INS1h) and body mass index (BMI) and lower insulin sensitivity (P<0.05). The incidence of IGT (or DM) was three fold higher in the lower insulin sensitivity tertile group than in the top tertiles (34.2% vs 11.9% and 9.5%, P<0.05). Logistic regression analysis demonstrated a significantly negative correlation between insulin sensitivity at baseline and development of IGT. Age, sex, BMI, PG2h and IS at baseline were not significantly correlated with IGT. Conclusion Insulin resistance is the most important risk factor of deteriorating glucose tolerance in subjects with NGT.