空腹血糖受损诊断标准下调的合理性分析

The rational of lowering criterion for impaired fasting glucose

目的 探讨空腹血糖受损 (IFG)诊断点从 6.1mmol/L下调至 5 .6mmol/L的合理性。方法对1986年入选的 468名非糖尿病人群〔3 41例正常糖耐量 (NGT) ,12 7例糖耐量受损 (IGT)〕在 1988年 ,1990年和 1992年分别进行OGTT复查 ,测定空腹血糖 (FPG)及 2h血糖 (2hPG)。以COX模型分析不同基线血糖水平增加糖尿病的风险。结果 (1) 10 9例 6年后发生糖尿病。COX成比例风险模型分析校正年龄、性别、体重指数 (BMI)影响后发现FPG与 2型糖尿病发病显著相关 (P =0 .0 0 0 1)。基线FPG 5 .6～ 6.0mmol/L组糖尿病发病危险性比FPG <5 .6mmol/L组已显著增加 ,RR为 3 .3 (95 %CI 2 .0～ 5 .3 ,P =0 .0 0 0 1)。 (2 )受试者工作特征 (ROC)曲线分析FPG预测糖尿病发病的最佳阈值是 5 .6mmol/L ,以FPG 5 .6mmol/L为诊断点IFG预报糖尿病发病的灵敏度、特异度、阳性预测值分别为 45 .0 % ,92 .8%和 65 .3 %。 (3 )NGT个体中COX成比例风险模型校正年龄、性别、BMI后显示 ,FPG分组 (5 .0～ 6.0mmol/L与 <5 .0mmol/L)与糖调节受损 (IGR ,包括IFG或IGT)发生显著正相关 (P =0 .0 0 7)。ROC曲线显示 ,FPG预测糖耐量恶化而进展为DM或IGR的最佳阈值为 5 .3mmol/L。结论 (1)本组非糖尿病人群中FPG预测糖尿病发病的最佳阈值为 5 .

Objective To investigate whether the lower threshold of impaired fasting glucose (IFG) should be revised from 6.1 mmol/L to 5.6 mmol/L. Methods 468 non-diabetic subjects [341 with normal glucose tolerance (NGT), 127 with impaired glucose tolerance (IGT)] enrolled in Daqing IGT and Diabetes Study as controls in 1986 were recruited in 1988, 1990 and 1992. Fasting plasma glucose (FPG) and 2h postprandial glucose (2hPG) during OGTT were assayed at baseline and follow-up visits. Results (1) 109 subjects (56 males and 53 females) progressed to diabetes mellitus (DM) during 6-year follow-up period and the cumulative incidence of diabetes increased as baseline FPG rose. Proportional hazard regression analysis revealed that relative risk of developing diabetes in group of FPG 5.6-6.0 mmol/L was 3.3 (95%CI 2.0-5.3, P=0.0001) compared with group of FPG<5.6 mmol/L after adjustment of age, sex and body mass index (BMI). (2) Receiver operating characteristic (ROC) curve analysis showed that the FPG value at the ideal of 100% sensitivity and 100% specificity in predicting future diabetes was 5.6 mmol/L. The sensitivity, specificity and positive predictive value of IFG for future diabetes were 45.0%, 92.8% and 65.3%, respectively. (3) Adjusting with age, sex and BMI, COX regression analysis showed that FPG group (5.0-6.0 mmol/L and <5.0 mmol/L) had significant correlation with development of impaired glucose regulation (IGR) and relative risk for developing IGR in group of FPG 5.0-6.0 mmol/L was 1.9 (95%CI 1.2-3.0),P=0.007, taking group of FPG<5.0 mmol/L as control. ROC analysis indicated that ideal cut point of FPG for future IGR or DM was 5.3 mmol/L in NGT subjects. Conclusion The lower threshold of IFG should be revised from 6.1 mmol/L to 5.6 mmol/L in Chinese population. In addition, attention should be paid to the subjects whose FPG have already reached 5.3 mmol/L, and they should be on the alert against deterioration to glucose intolerance.