Wong Vincent W, Garden Frances, Jalaludin Bin
Diabetes and Endocrine Service, Liverpool Hospital, Sydney, Australia.
Diabetes Res Clin Pract. 2009 Mar;83(3):394-6. doi: 10.1016/j.diabres.2008.11.026. Epub 2009 Jan 4.
The 50g-glucose challenge test (GCT) is commonly used for screening of gestational diabetes (GDM) in low risk pregnant women. If elevated, glucose tolerance test is performed to confirm the diagnosis. In this study, we evaluated whether GCT alone is sufficient to diagnose GDM when the GCT result is very elevated.
Using a database of 62877 pregnancies over 10 years, the positive predictive value (PPV) of GCT for GDM was assessed using different GCT cut-off values.
At a glucose cut-off value of 11 mmol/l, the PPV for GDM was 85.3%, based on the subsequent GTT. This increased to 95.3% when the cut-off was 12 mmol/l. Furthermore, the PPV was consistently higher when GCT was performed in the morning.
We concluded that the diagnosis of GDM can be made when the glucose level following GCT is very elevated, and GTT need not to be performed for confirmation of GDM. The timing of GCT also affected PPV for GDM, and has implications on the diagnostic value of the test.
50克葡萄糖耐量试验（GCT）常用于低风险孕妇的妊娠期糖尿病（GDM）筛查。若结果升高，则进行葡萄糖耐量试验以确诊。在本研究中，我们评估了当GCT结果大幅升高时，仅通过GCT是否足以诊断GDM。
利用一个包含10年间62877例妊娠的数据库，采用不同的GCT临界值评估GCT对GDM的阳性预测值（PPV）。
基于后续的葡萄糖耐量试验（GTT），当血糖临界值为11毫摩尔/升时，GDM的PPV为85.3%。当临界值为12毫摩尔/升时，该值增至95.3%。此外，上午进行GCT时，PPV始终更高。
我们得出结论，当GCT后的血糖水平大幅升高时，可诊断GDM，无需进行GTT来确诊GDM。GCT的时间安排也会影响GDM的PPV，对该检测的诊断价值有影响。
