摘要
目的 探讨判别两种成人隐匿性自身免疫糖尿病(LADA)亚型的最佳谷氨酸脱羧酶抗体(GAD-Ab)界值及其诊断价值。 方法 绘制LADA患者GAD-Ab指数的频数分布图,进行曲线拟合。比较130例经典1型糖尿病、145例2型糖尿病和145例LADA患者的临床特点,利用受试者运筹特征(ROC)曲线比较不同GAD-Ab滴度对LADA患者中反映 LADA 1 型特征的胰岛素缺乏和反映LADA 2型特征的代谢综合征(MS)的诊断价值,确定诊断两种 LADA亚型的最佳 GAD-Ab界值。用放射配体法测定 GAD-Ab。 结果 (1) GAD-Ab 频数在 LADA患者中呈双峰分布模式。(2)以GAD Ab指数0.3为切点所区分的两组LADA患者具有差异的临床特征最多。(3)ROC曲线显示GAD Ab指数0.3是区分两种LADA亚型的最佳界值,其对胰岛素缺乏和MS诊断的敏感性和特异性分别为54 5%和92 1%,ROC曲线下面积为 0.79(与 0.5 相比,P<0.01)。 结论 GAD Ab指数0 3是区分LADA-1型和LADA-2型的最佳界值。
Objective To investigate the optimal cut-point of glutamate decarboxylase antibody (GAD-Ab) for differentiating two subtypes of latent autoimmune diabetes in adults (LADA). (Methods) The frequency distribution of GAD-Ab index in LADA was described, and the estimated curve was made. The clinical features were compared among 145 LADA, 145 type 2 and 130 type 1 diabetic patients. Receiver-operating characteristic (ROC) curve was used to evaluate the diagnostic value of GAD-Ab in insulin-deficiency (representing LADA-1 subtype) and metabolic syndrome (representing LADA-2 subtype), and the optimal cut- point of GAD-Ab was defined. GAD-Ab was (measured) with radioligand assay. Results (1) The frequency distribution of GAD-Ab index in (LADA) was bimodal. (2) The number of clinical features which had significant differences in the patients of two subgroups was increased when cut-point moved from index of 0.1 to 0.3; however, there was a contrary tendency when the cut-point moved from index of 0.4 to 0.7. (3) ROC curve demonstrated that the optimal cut-point for the diagnosis of two subtypes of LADA was at 0.3, with sensitivity and specificity of 54.5% and 92.1% respectively for insulin-deficiency and metabolic syndrome. The area under ROC curve was 0.79 (compared with 0.5, P<0.01). Conclusions The optimal cut-point for the (differentiation) of two subtypes of LADA was at the GAD-Ab index of 0.3.
基金
湖南省卫生厅重点项目(2001 Z04)
湖南省科技厅项目(02SSY3065)
