Diabetes Care, Vol 21, Issue 9 1521-1524, Copyright © 1998 by American Diabetes Association
Urinary albumin excretion rate and glomerular filtration rate in single-kidney type 2 diabetic patients
SP Silveiro, LA da Costa, MO Beck and JL Gross
Endocrine Division, Hospital de Clinicas de Porto Alegre, Brazil.
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 non-diabetic patients (SKN). RESEARCH 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 nephrectomy and with no
calculus or systemic disease at the time of the evaluation, were included
in this controlled cross-sectional study A total 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 patients 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 51Cr-EDTA single-injection method. RESULTS: SKD patients
presented a higher proportion (8 of 20, 40%) of microalbuminuria (UAER
20-200 microg/min) than SKN patients (3 of 17, 17.6%) and type 2 diabetic
patients (37 of 184, 20%). SKD patients presented a higher proportion of
macroalbuminuria (UAER >200 microg/min; 6 of 20, 30%) than SKN patients
(1 of 17, 6%) but were similar to type 2 diabetic patients (43 of 184,
23%). The GFRs of normoalbuminuric SKN (71.7 +/- 21.4 ml x min(-1) x 1.73
m(-2)) and SKD patients (73.0 +/- 21.5 ml x min(-1) x 1.73 m(-2)) were
similar but higher than the one-kidney GFR (GFR / 2) of the age-, sex-, and
BMI-matched normal individuals (50.5 +/- 9.0 ml x min(-1) x 1.73 m(-2)) and
normoalbuminuric type 2 diabetic patients (54.0 +/- 11.6 ml x min(-1) x
1.73 m(-2)). CONCLUSIONS: Increased GFR related to single-kidney status
confers an increased risk of developing renal disease in the presence of
diabetes.