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Spot Urine Protein-to-Creatinine Ratio to Predict the Magnitude of 24-Hour Total Proteinuria in Preeclampsia of Varying Severity

      Abstract

      Objective

      The predictive value of spot urine protein-to-creatinine ratio (PCR) for estimating total 24-hour proteinuria in severe preeclampsia is unclear. This study aimed to assess the diagnostic accuracy of spot urine PCR for ascertaining the magnitude of proteinuria in women with preeclampsia of varying severity.

      Methods

      A total of 205 patients with prediagnosed preeclampsia were included in this prospective cohort study. Patients were allocated into one of the three groups categorized by severity of disease, as follows: gestational hypertension, group 1 (n = 41); preeclampsia, group 2 (n = 88); and severe preeclampsia, group 3 (n = 76). We assessed the spot urine PCRs to determine significant proteinuria and the magnitude of proteinuria in these groups.

      Results

      The spot urine PCR was 0.53, with 81% sensitivity and 93% specificity to detect significant proteinuria. A significant correlation was found between PCR and 24-hour total proteinuria in group 1 (r = 0.473, P = 0.002). There were also significant correlations in group 2 (r = 0.814, P < 0.001) and group 3 (r = 0.912, P < 0.001). The established formula using spot urine PCR to estimate 24-hour total proteinuria in severe preeclampsia was Y = 832.02X + 378.74 mg (r2 = 0.8304).

      Conclusion

      Although 24-hour urine collection remains a merely reliable test to determine the degree of total proteinuria, our findings suggest that it is likely to assess the magnitude of proteinuria by the spot urine PCR, especially in severe preeclampsia.

      Clinical trial registration

      Résumé

      Objectifs

      On ne connaît pas exactement la valeur prédictive du rapport protéinurie/créatininurie (RPC) d'une miction isolée pour estimer la protéinurie sur 24 heures en cas de prééclampsie grave. Cette étude visait donc à évaluer la précision diagnostique de cette méthode pour évaluer l'importance de la protéinurie chez des femmes atteintes de prééclampsie à divers degrés de gravité.

      Méthodologie

      Nous avons mené une étude de cohorte prospective auprès de 205 patientes ayant déjà reçu un diagnostic de prééclampsie. Les patientes ont été réparties dans trois groupes selon la gravité de leur état : hypertension gravidique (groupe 1; n = 41); prééclampsie (groupe 2; n = 88); prééclampsie grave (groupe 3; n = 76). Nous avons ensuite évalué le RPC de mictions isolées afin de détecter les cas de protéinurie marquée et de déterminer l'importance de la protéinurie.

      Résultats

      Nous avons utilisé une valeur de RPC de mictions isolées de 0,53; la sensibilité et la spécificité pour la détection d'une protéinurie marquée étaient respectivement de 81 % et de 93 %. Nous avons observé une corrélation significative entre le RPC et la protéinurie totale sur 24 heures dans le groupe 1 (r = 0,473; P = 0,002), le groupe 2 (r = 0,814; P < 0,001) et le groupe 3 (r = 0,912; P < 0,001). La formule établie pour estimer la protéinurie sur 24 heures à partir du RPC d'une miction isolée chez les cas de prééclampsie grave était la suivante : Y = 832,02X + 378,74 mg (r2 = 0,8304).

      Conclusion

      Bien que la collecte d'urine sur 24 heures demeure d'une certaine fiabilité pour déterminer le degré de protéinurie totale, nos résultats indiquent qu'il serait possible d'évaluer l'importance de la protéinurie à l'aide du RPC d'une miction isolée, plus particulièrement dans les cas de prééclampsie grave.

      Clinical trial registration

      Key Words

      Abbreviations:

      AUC (area under the curve), PCR (protein-to-creatinine ratio), ROC (receiver operating characteristic)
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