Spot morning urine protein creatinine ratio and 24 hour urinary total protein excretion rate

Abstract

Proteinuria helps to establish the diagnosis of most renal diseases and also to predict the outcome of such diseases. Proteinuria is biochemically represented by measuring the protein concentration in timed collection of 24 hour urine. But, 24-hour timed urine collection is time consuming, cumbersome and often unreliable due to collection errors and also results in undue delay on diagnostic process. An alternate approach avoiding arduous and inaccurate timed urine collection can be the measurement of protein creatinine ratio in spot morning urine. This study was aimed to evaluate whether the spot morning urine protein creatinine ratio can be a reliable alternative to 24-hour urinary total protein (UTP) estimation. The study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka on 50 (fifty) non-diabetic Chronic Renal Disease (CRD) patients with an age ranging from 18 -70 years. The study subjects were grouped into mild, moderate and severe CRD on the basis of GFR. Urinary protein and creatinine concentrations were measured in spot morning urine samples and their ratios were calculated. Urinary protein measured in 24-hour timed collected urine samples gave the 24-hour UTP excretion rate. In our study, spot morning urine protein creatinine ratio significantly correlated with 24-hour UTP excretion rate in all CRD patients. Severe CRD patients gave significant positive correlation (p<0.05), whereas mild and moderate CRD patients gave very highly significant positive correlation (p<0.001). Therefore, it may be suggested that protein creatinine ratio in spot morning urine can be accepted as a reliable and alternative to 24-hour UTP excretion rate in non-diabetic chronic renal disease patients. This simple and inexpensive procedure will thus simplify the way of establishing the severity of renal disease along with its prognosis.