Balion Cynthia M, Raina Parminder S, Gerstein Hertzel C, Santaguida P Lina, Morrison Katherine M, Booker Lynda, Hunt Dereck L
Department of Laboratory Medicine, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Clin Chem Lab Med. 2007;45(9):1180-5. doi: 10.1515/CCLM.2007.505.
The classifications of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) represent glucose levels above normal, but below the decision threshold for diabetes. We sought to determine what the reproducibility of these classifications was when repeat tests were performed by conducting a systematic review of the literature.
All primary studies published in English of any study design were included. Studies were excluded if they did not follow the World Health Organization or American Diabetes Association diagnostic criteria, used whole blood as the specimen type, a glucose meter for analysis, or performed repeat testing greater than 8 weeks apart.
Five papers had reproducibility data for IGT or IFG, two of which where from the same population but sampled differently. The kappa coefficients, indicating agreement between repeat tests that exceeded chance, indicated poor to fair agreement for IGT (0.04, 0.22, 0.38, 0.42) and moderate agreement for IFG (0.44 and 0.56). Similarly, the observed reproducibility was slightly lower for IGT (33%, 44%, 47%, 48%) compared to IFG (51%, 64%). In two studies for which data were available for both IGT and IFG, the average reproducibility was lower (49%) for the prediabetes group compared to the diabetes group (73%) or the normal group (93%).
Poor reproducibility of IGT and IFG classification suggests caution should be exercised when interpreting a single test result.
糖耐量受损（IGT）和空腹血糖受损（IFG）的分类代表血糖水平高于正常，但低于糖尿病的诊断阈值。我们试图通过对文献进行系统综述来确定重复检测时这些分类的可重复性如何。
纳入所有以英文发表的任何研究设计的原发性研究。如果研究未遵循世界卫生组织或美国糖尿病协会的诊断标准、使用全血作为标本类型、使用血糖仪进行分析或重复检测间隔超过8周，则将其排除。
五篇论文有IGT或IFG的可重复性数据，其中两篇来自同一人群但抽样方式不同。kappa系数表明重复检测之间的一致性超过了偶然因素，显示IGT的一致性较差至中等（0.04、0.22、0.38、0.42），IFG的一致性中等（0.44和0.56）。同样，与IFG（51%、64%）相比，IGT的观察到的可重复性略低（33%、44%、47%、48%）。在两项同时有IGT和IFG数据的研究中，与糖尿病组（73%）或正常组（93%）相比，糖尿病前期组的平均可重复性较低（49%）。
IGT和IFG分类的可重复性较差表明，在解释单次检测结果时应谨慎。
