Normoalbuminuria ensures no reduction of renal function in type 1 (insulin-dependent) diabetic patients.
Recent reports have suggested that impaired renal function in type 1 diabetic patients may be present despite normal urinary albumin excretion (UAE). We have studied kidney function by means of a constant-infusion technique in normoalbuminuric type 1 diabetic patients without antihypertensive medication (UAE less than 20 micrograms min-1, n = 134), in microalbuminuric patients (20 greater than or equal to UAE less than 200 micrograms min-1, n = 50) and in 27 non-diabetic control subjects. Mean UAE was 4.5 micrograms min-1 (range 1.0-19.3 micrograms min-1) in normoalbuminuric patients, 53.1 micrograms min-1 (range 20.8-147.5 micrograms min-1) in microalbuminuric patients, and 4.0 micrograms min-1 (range 2.1-17.9 micrograms min-1) in controls. Glycosylated haemoglobin A1c was significantly higher in microalbuminuric patients (8.9%, range 5.9-12.6%) than in normoalbuminuric patients (7.9%, range 5.5-11.5%) (P less than 0.0001). Glomerular filtration rate in normoalbuminuric patients (135 ml min-1, range 97-198 ml min-1) was significantly higher than in controls (118 ml min-1, range 94-139 ml min-1) (P less than 1 x 10(-6), and significantly lower than in microalbuminuric patients (142 ml min-1, range 100-186 ml min-1) (P less than 0.05). Mean arterial blood pressure was lower in normoalbuminuric patients (91 mmHg, range 78-108 mmHg) than in microalbuminuric patients (98 mmHg, range 82-131 mmHg) (P less than 1 x 10(-6), but not significantly different from that of controls (89 mmHg, range 73-103 mmHg). We conclude that normal UAE is a reliable indicator of well-preserved renal function. Glomerular hyperfiltration, elevated blood pressure and poor metabolic control are characteristic features of microalbuminuric patients.
Hansen
K W
KW
Medical Department M (Diabetes and Endocrinology), Aarhus Kommunehospital, Denmark.
Mau Pedersen
M
M
Christensen
C K
CK
Schmitz
A
A
Christiansen
J S
JS
Mogensen
C E
CE
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000503:physiopathology / Q000652:urine*; D000704:Analysis of Variance; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology / Q000652:urine*; D003928:Diabetic Nephropathies / Q000503:physiopathology / Q000652:urine*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012044:Regression Analysis