URINARY ALBUMIN EXCRETION RATE AND GLOMERULAR-FILTRATION RATE IN SINGLE-KIDNEY TYPE-2 DIABETIC-PATIENTS

OBJECTIVE - To evaluate the urinary albumin excretion rate (UAER) and the glomerular filtration rate (GFR) of single-kidney type 2 diabetic patients (SKD) and of single-kidney nondiabetic patients (SKN). RESEAR CH DESIGN AND METHODS - Patients who had only one kidney for at least 5 years, with no renal disease or hypertension at the time of the neph rectomy and with no calculus or systemic disease at the time of the ev aluation, were included in this controlled cross-sectional study. A to tal of 20 SKD (8 men, age 62 +/- 9 years; diabetes duration 8.5 +/- 7 years), 17 SKN (2 men, age 57 +/- 13 years), and 184 type 2 diabetic p atients who were matched to the single-kidney diabetic group for age, sex, and BMI were studied. UAER was measured by immunoturbidimetry in timed 24-h sterile urine, and GFR was determined by the Cr-51-EDTA sin gle-injection method. RESULTS - SKD patients presented a higher propor tion (8 of 20, 40%) of microalbuminuria (UAER 20-200 mu g/min) than SK N patients (3 of 17, 17.6%) and type 2 diabetic patients (37 of 184, 2 0%). SKD patients presented a higher proportion of macroalbuminuria (U AER >200 mu g/min; 6 of 20, 30%) than SKN patients (1 of 17, 6%) but w ere similar to type 2 diabetic patients (43 of 184, 23%). The GFRs of normoalbuminuric SKN (71.7 +/- 21.4 ml . min(-1) . 1.73 m(-2)) and SKD patients (73.0 +/- 21.5 mi min-l 1.73 m-2) were similar but higher th an the one-kidney GFR (GFR divided by 2) of the age-, sex-, and BMI-ma tched normal individuals (50.5 +/- 9.0 ml . min(-1) . 1.73 m(-2)) and normoalbuminuric type 2 diabetic patients (54.0 +/- 11.6 ml . min-l 1. 73 m-2). CONCLUSIONS - Increased GFR related to single-kidney status c onfers an increased risk of developing renal disease in the presence o f diabetes.