Concomitance of diabetic retinopathy and proteinuria accelerates the rate of decline of kidney function in type 2 diabetic patients.
OBJECTIVE
To evaluate the rate of progression of renal disease in proteinuric type 2 diabetic patients with and without retinopathy.


METHODS
Thirty-eight proteinuric type 2 diabetic patients with diabetic retinopathy and 27 without were enrolled in an observational study for the evaluation of rate of glomerular filtration rate (GFR) decline and followed up for a median period of 6 years. GFR was determined at least once per year, and blood pressure, glycated hemoglobin, and proteinuria were determined every 4 months.


RESULTS
Although the two groups had comparable GFR, albuminuria, blood pressure, and HbA(1c) at entry of the study, the rate of decline of GFR was higher in type 2 diabetic patients with retinopathy (-6.5 +/- 4.4 ml/year) than in those without (-1.8 +/- 4.8 ml/year; P < 0.0001). Protein and albumin excretion rate increased significantly in patients with retinopathy, while they did not change in those without. Mean blood pressure between the two groups of patients were similar both at entry and during the follow-up, although the proportion of patients treated with at least two antihypertensive drugs was higher in patients with retinopathy. On a multiple regression analysis, only mean blood pressure and proteinuria were significant determinants of progression of renal disease in type 2 diabetic patients with retinopathy.


CONCLUSIONS
The rate of progression of renal disease in proteinuric type 2 diabetic patients with retinopathy is faster than that observed in those without retinopathy. The screening for retinopathy identifies patients at high risk for rapid deterioration of kidney function.
Trevisan
Roberto
R
Unit for Metabolic Diseases, Department of Clinical and Experimental Medicine, University of Padova, Padova, Italy. rtrevisan@ospedaliriuniti.bergamo.it
Vedovato
Monica
M
Mazzon
Cinzia
C
Coracina
Anna
A
Iori
Elisabetta
E
Tiengo
Antonio
A
Del Prato
Stefano
S
D000419:Albuminuria; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000150:complications / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000150:complications / Q000503:physiopathology*; D012907:Smoking; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D000959:Antihypertensive Agents; D002784:Cholesterol; D006442:Glycated Hemoglobin; D014280:Triglycerides