Лого Српског лекарског друштва

Часопис Српског лекарског друштва

Српски архив за целокупно лекарство

Serbian Archives of Medicine

еКорпус – библиографски запис

Да ли је однос протеина и креатинина у јутарњем узорку мокраће поуздан у процени дневне протеинурије код особа с различитим болестима бубрега?

Is Morning Urinary Protein-to-Creatinine Ratio a Reliable Estimator of 24-Hour Proteinuria in Patients with Kidney Diseases?

Višnja Ležaić; Stojanka Ristić; Violeta Dopsaj; Jelena Marinković

Часопис
Serbian Archives of Medicine
Објављено
Srp Arh Celok Lek. 2010;138(11–12):726–731.
Врста рада
ORIGINAL ARTICLES

Abstract

Introduction Proteinuria is the most frequent marker of kidney damage. Although 24-hour urinary proteinuria is the gold standard, the measurement of proteinuria from albumin urinary creatinine ratio is proposed as much useful metod.

Objective To evaluate the accuracy of urine protein-to-creatinine (P/Cr) ratio in morning urine specimens as compared with 24-hour total protein excretion for the measurement of proteinuria in patients with different kidney diseases and different renal function levels.

Methods Proteinuria in the studied patients was assessed by 24-hour protein excretion (24-hour PRT) and spot urine P/Cr ratio. The analysis of concordance between 24-hour PRT and P/ Cr was carried out using intraclass correlation coefficient (ICC), paired t-test and Bland-Altman plots. The discriminant cutoff values for spot urine P/Cr ratio in predicting 24-hour protein „threshold” excretion were determined using receiver operating characteristic curves (ROC), as well as sensitivity and specificity.

Results A total of 303 patients were included in the study. The concordance between 24-hour PRT and P/Cr ratio was excellent (ICC 0.931). Systematic overestimation of PRT by urinary P/ Cr ratio was disclosed (mean difference 0.138, p=0.011). The P/ Cr of 0.25 (sensitivity 0.90; specificity 0.96), 0.66 (1.00; 0.91) and 2.55 (1.0; 0.97) g/g reliably predicted 24-hour urine total protein equivalent „thresholds” at 0.2, 1.0 and 3.5 g/day. The chronic renal failure group independently positively influenced the difference between 24-hour PRT and P/Cr. It means the lower the kidney function the higher is the difference between the two proteinuria measurements.

Conclusion This study supports the recommendation of using spot urine P/Cr ratio in proteinuria screening in patients with different kidney diseases. The obtained results indicated better agreement between morning P/Cr and 24-hour PRT in patients with lower proteinuria and better kidney function.

Keywords: proteinuria; spot morning urine; different kidney diseases