Studies in 156 young men at the Renal Unit, University of Singapore Department of Medicine, Singapore, for asymptomatic proteinuria and hematuria showed that patients with microscopic hematuria had a significantly higher prevalence of abnormal renal histological findings, raised erythrocyte sedimentation rate, and total urinary protein excretion of more than 500 mg/day. Within the group of patients with hematuria, there was also a significantly larger number of patients with abnormal renal histological findings who were excreting an abnormal quantity of urinary protein as compared with those having a normal renal histological appearance. All subjects with isolated orthostatic proteinuria and all but four patients with persistent proteinuria had normal renal histological findings.
In patients with hematuria, the presence of raised sedimentation rate and an abnormal quantity of urinary protein excretion indicate underlying renal parenchymal disease, while patients with isolated orthostatic proteinuria or persistent proteinuria have relatively normal results in renal biopsy studies.