Diabetes Care, Vol 21, Issue 7 1076-1079, Copyright © 1998 by American Diabetes Association

ARTICLES

Proteinuria is still useful for the screening and diagnosis of overt diabetic nephropathy

T Zelmanovitz, JL Gross, J Oliveira and MJ de Azevedo
Endocrine Unit, Hospital de Clinicas de Porto Alegre, Federal University of Rio Grande do Sul, Brazil.

OBJECTIVE: To assess the performance of urinary total protein measurements in timed 24-h urine collection (24-h UP) and in a diurnal random urine specimen (RUS) for the screening and diagnosis of overt diabetic nephropathy. RESEARCH DESIGN AND METHODS: A total of 167 diabetic patients (20 type 1 and 147 type 2 diabetic patients; 78 women and 89 men), aged 20-84 years, collected 217 timed 24-h urine specimens. Albumin was measured by immunoturbidimetry, total protein by sulfosalicylic acid technique, and creatinine by Jaffe's method. According to the timed 24-h urinary albumin excretion rate (UAER), samples were divided into three groups: normoalbuminuric (NORMO) (UAER < 20 micrograms/min; n = 84), microalbuminuric (MICRO) (UAER 20-200 micrograms/min; n = 78), and macroalbuminuric (MACRO) (UAER > or = 200 micrograms/min; n = 55). Eighty-six patients also collected 105 RUSs (NORMO, n = 47; MICRO, n = 37; MACRO, n = 21), and urinary protein concentration (UPC) and urinary protein-to-creatinine ratio (UPCR) were measured. The receiver operating characteristics (ROC) curve approach was used to analyze the performance of the diagnostic tests. RESULTS: Spearman's coefficient of correlation of 24-h UAER versus 24-h UP was 0.95 (P < 0.001), and of 24-h UAER versus UPC and UPCR were 0.77 and 0.72, respectively (P < 0.001). The calculated areas (+/- SEM) under the ROC curve for the diagnosis of over diabetic nephropathy were 0.9987 +/- 0.001 for 24-h UP, 0.9926 +/- 0.006 for UPC, and 0.9751 +/- 0.014 for UPCR. In the ROC curves, the first points with 100% sensitivity were 541 mg (95.7% specificity) for 24-h UP, 431 mg/l (92.9% specificity) for UPC, and 0.2 (76.2% specificity) for UPCR. CONCLUSIONS: Measurements of proteinuria presented almost perfect accuracy for the screening and diagnosis of overt diabetic nephropathy. Protein measurement in spot urine is a reliable and simple method for the screening and diagnosis of overt diabetic nephropathy.
CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				J. L. Camargo, G. M. Lara, A. E. Wendland, J. L. Gross, and M. J. de Azevedo Agreement of Different Immunoassays for Urinary Albumin Measurement Clin. Chem., May 1, 2008; 54(5): 925 - 927. [Full Text] [PDF]

				B. Kestenbaum, K. D. Rudser, I. H. de Boer, C. A. Peralta, L. F. Fried, M. G. Shlipak, W. Palmas, C. Stehman-Breen, and D. S. Siscovick Differences in Kidney Function and Incident Hypertension: The Multi-Ethnic Study of Atherosclerosis Ann Intern Med, April 1, 2008; 148(7): 501 - 508. [Abstract] [Full Text] [PDF]

				G. P. Rossi, G. Bernini, G. Desideri, B. Fabris, C. Ferri, G. Giacchetti, C. Letizia, M. Maccario, M. Mannelli, M.-J. Matterello, et al. Renal Damage in Primary Aldosteronism: Results of the PAPY Study Hypertension, August 1, 2006; 48(2): 232 - 238. [Abstract] [Full Text] [PDF]

				J. L. Gross, M. J. de Azevedo, S. P. Silveiro, L. H. Canani, M. L. Caramori, and T. Zelmanovitz Diabetic Nephropathy: Diagnosis, Prevention, and Treatment Diabetes Care, January 1, 2005; 28(1): 164 - 176. [Abstract] [Full Text] [PDF]

				V Mohan, R Meera, G Premalatha, R Deepa, P Miranda, and M Rema Frequency of proteinuria in type 2 diabetes mellitus seen at a diabetes centre in southern India Postgrad. Med. J., September 1, 2000; 76(899): 569 - 573. [Abstract] [Full Text]