Urinary protein/creatinine ratio in hypertensive pregnant women

Objectives: To determine the correlation between the protein/creatinine rat io and 24-h proteinuria; to estimate the sensitivity and specificity of thi s ratio for the diagnosis of significant proteinuria; to establish its cuto ff point with the best predictive value for the diagnosis of significant pr oteinuria in patients with systemic arterial hypertension. Study Design: A cross-sectional study of 47 hypertensive patients who had b een pregnant for 20 weeks or more seen at the Maternity of the University H ospital of Porto Alegre. The studied factor was the protein/creatinine rati o measured in a single random urine sample and the outcome was protein dete rmination in 24-h urine. The level of significance was set at 0.05. Results: The correlation coefficient between the protein/creatinine ratio a nd 24-h proteinuria was 0.94 when urine was properly collected. A receiver- operator characteristic curve was constructed to determine the sensitivity and specificity of the ratio for the diagnosis of significant proteinuria ( greater than or equal to 300 mg in 24 h). Specificity and predictive positi ve value were 100% for a ratio greater than or equal to 0.8. The best value s for sensitivity, specificity, positive predictive value, and negative pre dictive value in the diagnosis of proteinuria greater than or equal to 300 mg in 24 h were obtained when the protein/creatinine ratio was 0.5 (0.96, 0 .96, 0.96, and 0.96, respectively). Conclusion: The protein/creatinine ratio measured in a single urine sample taken at random from hypertensive pregnant women showed good sensitivity an d specificity for the diagnosis of 24-h proteinuria greater than or equal t o 300 mg and was strongly correlated with 24-h proteinuria. A ratio of 0.5 mg/mg is predictive of significant proteinuria and can be used for the diag nosis and follow-up of hypertensive pregnant women.