2型糖尿病一级亲属的胰岛素敏感性和胰岛β细胞功能

目的　研究胰岛素抵抗和胰岛 β细胞功能在 2型糖尿病发生发展中的作用。 方法　对6 14例既往无糖耐量异常病史的 2型糖尿病患者的一级亲属进行口服 75克葡萄糖耐量试验 (OGTT)和糖化血红蛋白 (HbA1c)测定 ,根据单次检验结果 ,118(19 2 % )例新诊断糖尿病 ,12 1(19 7% )例被诊断为空腹血糖受损 (IFG)和 /或糖耐量减低 (IGT) ,316例OGTT和HbA1c均正常 ,其中 5 9例OGTT正常而HbA1c高于正常。用HomaIR评估胰岛素抵抗 ,Homa β评估基础胰岛素分泌 ,OGTT中空腹和 30min胰岛素血糖差值的比值 (ΔI30 /ΔG30 )评价胰岛素早期分泌 ,用ΔI30 /ΔG30 /HOMAIR评估处置指数 (DI)。结果　糖耐量降低与胰岛素抵抗、β细胞功能下降相关 ,从正常糖耐量 (NGT)经IFG和IGT到糖尿病 (DM)状态 ,HomaIR进行性增加 (NGT为 0 76± 0 6 ,IFG/IGT为 1 0± 0 6 ,DM为 1 5± 0 6 ,均P <0 0 0 1) ,Homa β(NGT为 5 3± 0 7,IFG/IGT为 5 1± 0 7,DM为 4 1± 0 9)、I30 /ΔG30 (NGT为 2 8± 0 9,IFG/IGT为 2 2± 1 0 ,DM为 1 3± 1 0 )和DI(NGT为 2 0± 0 9,IFG/IGT为 1 1± 0 9,DM为 - 0 2± 1 2 )进行性下降 (均P <0 0 0 1)。根据OGTT曲线下面积(AUCg)三分位值 ,将正常糖耐量个体分为 3组 (1/ 3、2 / 3、3/ 3组 )

Insulin sensitivity and beta function in the first-degree relatives of type 2 diabetic patients

OBJECTIVE: To investigate the roles of insulin resistance and beta-cell function in the pathogenesis of type 2 diabetes mellitus. METHODS: 614 first-degree relatives without glucose intolerance history underwent an oral glucose test (OGTT) and their levels of HbA1c were determined. According to the single OGTT results and WHO criteria, 118 (19.2%) of the 614 subjects were newly diagnosed with diabetes, 121 (19.7%) with impaired glucose tolerance (IGT) or/and impaired fasting glucose (IFG), 375 with normal glucose tolerance (NGT), of which 316 (51.5%) subjects were with HbA1c in normal level range (4% approximately 6%) and the others with high HbA1c level (9.6%). Homeostasis model assessment of insulin resistance (Homa(IR)) was used to estimate insulin resistance, Homa-beta cell was used to evaluate basal insulin secretion, incremental glucose (DeltaG30) and insulin (DeltaI30) response was calculated as the difference between the values 30 min after glucose intake to evaluate the early insulin secretion, DeltaI30/DeltaG30/HOMA(IR) was used to evaluate the disposition index (DI). RESULTS: Decreasing glucose tolerance was associated with insulin resistance, beta cell function and DI. From normal glucose tolerance condition through IFG /IGT to diabetic, the Homa IR progressively increased (NGT 0.76 +/- 0.6, IFG/IGT 1.0 +/- 0.6, DM 1.5 +/- 0.6, P < 0.001), Homa-beta cell (NGT 5.3 +/- 0.7, IFG/IGT 5.1 +/- 0.7, DM 4.1 +/- 0.9), I30/DeltaG30 (NGT 2.8 +/- 0.9, IFG/IGT 2.2 +/- 1.0, DM 1.3 +/- 1.0) and DI (NGT 2.0 +/- 0.9, IFG/IGT 1.1 +/- 0.9, DM -0.2 +/- 1.2), progressively decreased (P < 0.001). Normal subjects were divided into three tertile groups with different area under the curve of OGTT glucose. After adjusted by sex, age, BMI and WHR, the upper terile group was found having high Homa IR and lower Homa-beta, DeltaI30/DeltaG30/, I than lower tertile group. CONCLUSION: Abnormal glucose tolerance is common in first-degree relatives of non-insulin-dependent Diabetes Mellitus patients, both insulin resistance and impaired beta cell function are associated with impaired glucose metabolism, which have existed before diagnosis of IFG, IGT and diabetes.