Ferrannini E, Massari M, Nannipieri M, Natali A, Ridaura R Lopez, Gonzales-Villalpando C
Department of Internal Medicine, University of Pisa School of Medicine, Pisa, Italy.
Diabetologia. 2009 May;52(5):818-24. doi: 10.1007/s00125-009-1289-8. Epub 2009 Feb 18.
AIMS/HYPOTHESIS: The value of diagnostic categories of glucose intolerance for predicting type 2 diabetes is much debated. We therefore sought to estimate relative and population-attributable risk of different definitions based on fasting (impaired fasting glucose [IFG]) or 2 h plasma glucose concentrations (impaired glucose tolerance [IGT]) and to describe the associated clinical phenotypes.
We prospectively observed a population-based cohort of 1,963 non-diabetic participants (mean age 47 years), in whom an OGTT was performed at baseline and 7 years later.
IGT was fivefold more prevalent (13.5%) than IFG. In both categories, participants were older, heavier, hyperinsulinaemic, hyperproinsulinaemic and dyslipidaemic compared with participants with normal glucose tolerance. Relative risk of incident diabetes was similar for IFG and IGT categories (3.73 [95% CI: 2.18-6.39] and 4.01 [95% CI: 3.12-5.14], respectively), but the population-attributable risk was fivefold higher for IGT (29% [95% CI: 26-32]) than for IFG (6% [95% CI: 5-7]). Isolated IFG carried no increase in risk. Lowering the threshold to 5.6 mmol/l raised the population-attributable risk of IFG to 23% (95% CI: 20-25); its contribution to diabetes progression, however, was largely due to co-existent IGT. In multivariate analysis adjusting for sex, age, familial diabetes and BMI, fasting and 2 h glucose were independent predictors.
CONCLUSIONS/INTERPRETATION: Fasting and 2 h glucose values are independent predictors of incident diabetes. Isolated IFG is not a high-risk condition; lowering the diagnostic threshold increases the population-attributable risk of IFG fourfold, but performing an OGTT captures additional diabetes progressors compared with the number identified by IFG.
目的/假设：葡萄糖耐量异常的诊断类别对预测2型糖尿病的价值存在诸多争议。因此，我们试图估算基于空腹血糖（空腹血糖受损[IFG]）或2小时血浆葡萄糖浓度（糖耐量受损[IGT]）的不同定义的相对风险和人群归因风险，并描述相关的临床表型。
我们前瞻性观察了一个基于人群的队列，其中包括1963名非糖尿病参与者（平均年龄47岁），在基线时和7年后对他们进行了口服葡萄糖耐量试验（OGTT）。
IGT的患病率（13.5%）是IFG的五倍。与葡萄糖耐量正常的参与者相比，这两类参与者年龄更大、体重更重、存在高胰岛素血症、高胰岛素原血症和血脂异常。IFG和IGT类别的糖尿病发病相对风险相似（分别为3.73[95%CI：2.18 - 6.39]和4.01[95%CI：3.12 - 5.14]），但IGT的人群归因风险（29%[95%CI：26 - 32]）比IFG（6%[95%CI：5 - 7]）高五倍。单纯IFG的风险没有增加。将阈值降低至5.6 mmol/l可使IFG的人群归因风险提高至23%（95%CI：20 - 25）；然而，其对糖尿病进展的贡献主要归因于并存的IGT。在对性别、年龄、家族性糖尿病和体重指数进行多变量分析时，空腹血糖和2小时血糖是独立的预测因素。
结论/解读：空腹血糖和2小时血糖值是糖尿病发病的独立预测因素。单纯IFG并非高危情况；降低诊断阈值可使IFG的人群归因风险增加四倍，但与IFG识别出的糖尿病进展者数量相比，进行OGTT可发现更多糖尿病进展者。
