2型糖尿病、糖耐量低减及糖尿病患者亲属胰岛β细胞功能变化的研究

Changes of islet β-cell function in the patients with type 2 diabetes, subjects of impaired glucose tolerance and relatives of diabetics

目的 观察四川地区 2型糖尿病 (DM )患者、糖耐量低减 (IGT)者及糖尿病血缘亲属的胰岛 β细胞功能的变化 ,包括血中胰岛素原 (PI)水平的变化及其意义。 方法 采用特异性胰岛素(I)、C肽 (CP)和人胰岛素原放射免疫分析试剂盒 (均为美国Linco公司产品 )测定了糖耐量正常(NGT)对照者 (A组 ,49例 )、2型DM血缘亲属NGT者 (B组 ,5 2例 )、IGT/空腹血糖升高 (IFG)者 (C组 ,33例 )和新诊断的 2型DM患者 (D组 ,81例 )的空腹及试餐后 2小时上述三种激素的浓度 ,进行了各组内肥胖和非肥胖两个亚组的比较 ,以及各大组间的对比分析。结果 (1)各组内三种激素在肥胖亚组均比非肥胖亚组高 ;(2 )排除了肥胖因素 ,I及CP在IGT/IFG组最高。在DM组有下降趋势 ,但三种激素的空腹值仍高于对照组和亲属组 ;(3)无论肥胖或非肥胖亚组 ,PI从A→B→C→D组呈递增趋势 ,在D组无下降趋势 ,仍继续增高 ;(4 )以PI/I及PI/CP比值 (% )进行组间比较 ,发现无论空腹抑餐后 ,均以DM组最高 ;(5 )以大于A组PI/I及PI/CP比值的x± 2s为判断标准 ,发现“不成比例”的PI/I增高者之检出率在A、B、C及D组分别为 6 .1%、9.6 %、2 7.3 %及 6 1.7% ;以PI/CP为参数则各组分别为 10 .2 %、32 .7%、30 .3 %和 44 .4%。结论 “不成比例”的PI分泌增加是 β?

Objective To observe the changes of islet β cell function in patients with type 2 diabetese, subjects with impaired glucose tolerance (IGT) and relatives of diabetics in Sichuan district, including change of serum proinsulin (PI) level and its significance. Methods Insulin (I), C peptide (CP) and human proinsulin were measured in fasting and 2h postprandial sera of newly diagnosed patients with type 2 diabetics (Group D, n=81), subjects of IGT/impaired fasting glucose (IFG) (Group C, n=33), consanquineous relatives of diabetics (Group B, n=52) and normal glucose tolerant subjects (Group A, n=49) by respective radioimmunoassay kits. The results were compared between the obese (including over weighted) and non obese (including non over weighted) subgroups in each group, and among the 4 groups mentioned above. Results (1)The three hormone levels were higher in the obese subgroups than those in the non obese subgroups in all 4 groups; (2)Subjects of IGT/IFG (Group C) had the highest levels of I and CP concentrations in the 4 groups. The I and CP concentrations of the diabetics (Group D) had a declining tendency compared with Group C, but the levels of the 3 hormones of Group D were still higher than those of group A and B respectively; (3)Either in the obese subgroups or in the non obese subgroups, and either for the fasting or for the postprandial sera, the PI level was increased stepwisely from Group A→B→C→D; (4)Using PI/I or PI/CP ratio (%) as parameters, the diabetic group had the highest ratio of PI/I either in the obese or in the non obese subgroup, and either in the fasting or the postprandial sera; (5)In the present study, the “disproportional” hyperproinsulinemia was defined when the calculated ratio of PI/I or PI/CP was higher than those of the control group by x ±2s. The occurrence rate in the corresponding group of disproportional hyperproinsulinemia(forPI/IorPI/CP)ofA, B, C, and D group were 6.1%、9.6%、27.3% and 61.7% or 10.2%、32.7%、30.3% and 44.4%respectively. Conclusion Disproportionately increased PI may be a part of the entity of β cell dysfunction and might be one of the predictive markers of type 2 diabetes mellitus.