Alternate evaluations of proteinuria in the gravid hypertensive patient.
OBJECTIVE
To determine if the 12-hour urine total protein value correlates with the 24-hour value and to evaluate the random protein:creatinine ratio as a predictor of significant proteinuria (> or = 300 mg/24 h) for use in diagnosing preeclampsia.


METHODS
The study population included 15 patients with hypertensive disorders of pregnancy. The patients' urine was collected over 24 hours in 2 12-hour aliquots. The urine volume, total protein and creatinine were measured. The patients' initial voids were collected and evaluated for random urine protein and creatinine and calculation of the protein:creatinine ratio. The protein:creatinine ratio and 12-hour results were compared to the 24-hour results using simple regression analysis.


RESULTS
Of the 15 patients, 6 had no proteinuria, 5 had mild proteinuria, and 4 had severe proteinuria (60% with significant proteinuria). The 12-hour protein results correlated with the 24-hour results for patients with mild disease (p = 0.00007, first 12 hours, and p = 0.012, second 12 hours) and severe disease (p = 0.014 and p = 0.007). The results for no disease were mixed: for the first 12 hours there was a poor correlation, but the results for the second 12 hours correlated well. The protein:creatinine ratio had a significant correlation (p = 0.02), using a cutoff of 0.15, returned specificity of 50%, sensitivity of 100%, positive predictive value of 75% and negative predictive value of 100%.


CONCLUSIONS
Total protein values for 12- and 24-hour urine samples correlate well for the diagnosis of preeclampsia. A protein:creatinine ratio of < or = 0.15 rules out significant proteinuria. In combination, these 2 tests may allow more rapid diagnosis of preeclampsia.
Schubert
Frank P
FP
Department of Obstetrics and Gynecology, Indiana University, Indianapolis, USA. fschuber@iupui.edu
Abernathy
Mary P
MP
D000328:Adult; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000175:diagnosis*; D011247:Pregnancy; D011507:Proteinuria / Q000652:urine*; D013997:Time Factors; D016482:Urinalysis / Q000379:methods / Q000592:standards*
D003404:Creatinine