Mild proteinuria in patients with unilateral kidney.

Arterial blood pressure, 24 h urinary excretion, and glomerular filtration rate (GFR) in 24 patients with unilateral kidney were compared with an age and sex matched control group of healthy persons. Of the patients with unilateral kidney, 13 were uninephrectomized and 11 patients had a congenital unilateral kidney. The 24 h urinary protein excretion in patients with one kidney was significantly higher (630 +/- 51 mg/24 h) compared to the control group (206 +/- 36 mg/24 h). The arterial systolic and diastolic blood pressures and GFR did not differ in both groups. Furthermore, no differences were found between patients with unilateral kidneys following nephrectomy or renal agenesis. This study shows that mild proteinuria occurs in patients with unilateral kidney. An increased risk for deterioration in renal function or severe arterial hypertension was not detected in this investigation.