Campos M A A, Reichelt A A J, Façanha C, Forti A C, Schmidt M I
Programa de Pós-Graduação em Epidemiologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
Braz J Med Biol Res. 2008 Aug;41(8):684-8. doi: 10.1590/s0100-879x2008000800008.
In order to evaluate the performance of a 1-h 75-g oral glucose tolerance test (OGTT) for the diagnosis of gestational diabetes mellitus (GDM), a cohort of 4998 women, 20 years or older, without previous diabetes being treated in prenatal care clinics in Brazil answered a questionnaire and performed a 75-g OGTT including fasting, 1-h and 2-h glucose measurements between their 24th and 28th gestational weeks. Pregnancy outcomes were transcribed from medical registries. GDM was defined according to WHO criteria (fasting: >/=126 mg/dL; 2-h value: >/=140 mg/dL) and macrosomia as a birth weight equal to or higher than 4000 g. Areas under the receiver operator characteristic curve (AUC) were compared and diagnostic properties of various cut-off points were evaluated. The AUCs for the prediction of macrosomia were 0.606 (0.572-0.637) for the 1-h and 0.589 (0.557-0.622) for the 2-h plasma glucose test. Similar predictability was demonstrable regarding combined adverse outcomes: 0.582 (0.559-0.604) for the 1-h test and 0.572 (0.549-0.595) for the 2-h test. When the 1-h glucose test was evaluated against a diagnosis of GDM defined by the 2-h glucose test, the AUC was 0.903 (0.886-0.919). The cut-off point that maximized sensitivity (83%) and specificity (83%) was 141 mg/dL, identifying 21% of the women as positive. A cut-off point of 160 mg/dL, with lower sensitivity (62%), had higher specificity (94%), labeling 8.6% as positive. Detection of GDM can be done with a 1-h 75-g OGTT: the value of 160 mg/dL has the same diagnostic performance as the conventional 2-h value (140 mg/dL). The simplification of the test may improve coverage and timing of the diagnosis of GDM.
为评估1小时75克口服葡萄糖耐量试验（OGTT）用于诊断妊娠期糖尿病（GDM）的性能，在巴西产前保健诊所就诊的4998名20岁及以上、既往无糖尿病史的女性队列回答了一份问卷，并在孕24至28周期间进行了75克OGTT，包括空腹、1小时和2小时血糖测量。妊娠结局从医疗记录中抄录。GDM根据世界卫生组织标准定义（空腹：≥126毫克/分升；2小时值：≥140毫克/分升），巨大儿定义为出生体重等于或高于4000克。比较了受试者工作特征曲线（AUC）下的面积，并评估了各种切点的诊断特性。1小时血浆葡萄糖试验预测巨大儿的AUC为0.606（0.572 - 0.637），2小时血浆葡萄糖试验为0.589（0.557 - 0.622）。对于联合不良结局，也显示出类似的预测能力：1小时试验为0.582（0.559 - 0.604），2小时试验为0.572（0.549 - 0.595）。当根据2小时葡萄糖试验定义的GDM诊断来评估1小时葡萄糖试验时，AUC为0.903（0.886 - 0.919）。使敏感性（83%）和特异性（83%）最大化的切点为141毫克/分升，将21%的女性判定为阳性。切点为160毫克/分升时，敏感性较低（62%），但特异性较高（94%），将8.6%的女性判定为阳性。使用1小时75克OGTT可以检测GDM：160毫克/分升的值与传统的2小时值（140毫克/分升）具有相同的诊断性能。试验的简化可能会改善GDM诊断的覆盖率和及时性。
