Zeynep Kamil Gynecologic and Pediatric Training and Research Hospital, Istanbul, Turkey.
Eur J Obstet Gynecol Reprod Biol. 2013 Oct;170(2):368-71. doi: 10.1016/j.ejogrb.2013.07.024. Epub 2013 Aug 6.
To compare the spot urine protein-to-creatinine (P/C) ratio and 24-hour urine protein excretion in pregnant women with preeclampsia and also to determine the best discriminator values of the spot P/C ratios for 300 mg and 2000 mg protein per 24h.
Prospective study of 200 pregnant women with new onset hypertension at or greater than 140/90 mmHg after 20 weeks of gestation. Women were instructed to collect urine during a 24-hour period, and after the 24-hour urine sample collection was completed a mid-stream urine specimen was obtained for P/C ratio determination. The correlation between 24-hour urine protein excretion and spot urine P/C ratio was calculated. The receiver operating characteristic (ROC) curve was used to identify the cut-off values of the spot P/C ratios for 300 mg and 2000 mg protein per 24h. Areas under ROC curves were calculated.
There was a significant correlation between 24-hour protein excretion and the urine P/C ratio (r=0.828, p<0.0001). The cut-off P/C ratio for 300 mg per 24h was 0.28: sensitivity and specificity were 60.4% and 77.9%, respectively. The positive predictive value (PPV) was 77.5% and negative predictive value (NPV) was 60.9%. The cut-off P/C ratio for 2000 mg per 24h was 0.77: sensitivity and specificity were 96.8% and 98.6%, respectively. The PPV was 96.8% and NPV was 98.6%. Area under ROC curves for 24-hour urine total protein of 300-2000 mg/day and >2000 mg/day were 0.74 (95% CI 0.66-0.80) and 0.99 (95% CI 0.95-0.99), respectively.
Spot P/C ratio is a poor predictor of 24-hour proteinuria but can predict proteinuria >2000 mg better than 300-2000 mg.
比较子痫前期孕妇的随机尿蛋白与肌酐（P/C）比值和 24 小时尿蛋白排泄量，并确定随机尿 P/C 比值区分 300mg 和 2000mg 尿蛋白的最佳截断值。
前瞻性研究了 200 例在妊娠 20 周后出现新发生的高血压（血压≥140/90mmHg）的孕妇。指导孕妇在 24 小时内收集尿液，在完成 24 小时尿液标本收集后，获得中段尿液标本以测定 P/C 比值。计算 24 小时尿蛋白排泄量与随机尿 P/C 比值之间的相关性。使用受试者工作特征（ROC）曲线确定随机尿 P/C 比值区分 300mg 和 2000mg 尿蛋白的最佳截断值。计算 ROC 曲线下面积。
24 小时蛋白排泄量与尿 P/C 比值之间存在显著相关性（r=0.828，p<0.0001）。300mg 尿蛋白的 P/C 比值截断值为 0.28，其灵敏度和特异性分别为 60.4%和 77.9%，阳性预测值（PPV）为 77.5%，阴性预测值（NPV）为 60.9%。2000mg 尿蛋白的 P/C 比值截断值为 0.77，其灵敏度和特异性分别为 96.8%和 98.6%，PPV 为 96.8%，NPV 为 98.6%。24 小时尿总蛋白 300-2000mg/天和>2000mg/天的 ROC 曲线下面积分别为 0.74（95%CI 0.66-0.80）和 0.99（95%CI 0.95-0.99）。
随机尿 P/C 比值是 24 小时蛋白尿的不良预测指标，但对 2000mg 以上蛋白尿的预测优于 300-2000mg。
