Quantification of proteinuria in mild preeclampsia with random albumin creatinine ratio

Abstract

Objective: To investigate the whether spot urine albumin/creatinine ratio (ACR) compared to the 24h urinary protein (gold standard) to detect significant proteinuria in patients with preeclampsia. Study design: 80 pregnant patients diagnosed to have hypertension in late pregnancy were instructed to collect urine during a 24-hour period. Albumin creatinine ratio was evaluated in a random urinary specimen and morning samples for quantization of proteinuria. Out of these, 78 patients fulfilled the inclusion criteria. The predictive value of the random urinary ACR for the diagnosis of significant proteinuria was estimated by using various cutoff values of urinary ACR in comparison to 24-h urine collection as the gold standard. Results: 70 (89%) patients had preeclampsia. The mean morning systolic blood pressure on the day of the urine collections was 150 mmHg and mean diastolic blood pressure 114 mmHg. The mean total protein was 1961.46+1683.02 mg/24h, and the urinary ACR in random samples was 781.31+1041 mg/g creatinine, while in the morning sample urinary ACR was 886.43+1180.9 mg/g creatinine. There was a statistically significant positive correlation between in 24-hours urine proteins and ACR in both daytime and morning urine samples. The best cutoff point for ACR in random sample was 262.5 mg /g creatinine as with a sensitivity of 85.5% and a specificity of 81.8%, the positive predictive value was 96.7% and negative predictive value was 47.4%. While the best cutoff point for ACR in morning sample was 240 mg /g creatinine with a sensitivity of 94.2% and a specificity of 63.6%, the positive predictive value was 94.2% and negative predictive value was 63.6%. Conclusion: Albumin/creatinine ratio is not an ideal diagnostic test to replace 24-hour urine collection for the diagnosis of preeclampsia. However, it can be used as a screening test with sensitivity 94% when the cut point of albumin/creatinine ratio of the morning urine sample is set below 240 mg/g creatinine. Key