How to measure proteinuria?

Abstract

Purpose of review: To examine the use of urine total protein compared with albumin measurements to assess and monitor patients with chronic kidney disease.

Recent findings: Urine albumin or total protein-to-creatinine ratio measurements on a single-voided specimen provide a convenient and reliable alternative to 24-h urine measurements. The majority of studies that inform current renoprotective strategies have relied upon urine total protein measurements. Urine albumin measurements are required to detect microalbuminuria. The proportion of urinary protein composed of albumin is variable and may depend on the underlying renal disease.

Summary: Urine protein-to-creatinine measurements should continue to be used for the assessment and monitoring of patients with nondiabetic chronic kidney disease. Urine albumin-to-creatinine measurements should be reserved for detecting microalbuminuria and monitoring patients with diabetic nephropathy. Further research is required to investigate the relationship between urine total protein and albumin in different renal diseases and to compare the prognostic significance of urine total protein with that of albumin.