Urine Albumin: What Protein in Urine Can Signal

Urine albumin is a test for the presence of the protein albumin in urine, also called albuminuria. Urine albumin is measured on a spot urine sample along with creatinine, and the result is reported as the albumin-to-creatinine ratio (ACR).

Detection of albumin in urine is important because albuminuria is often the first sign of kidney damage. In people with diabetes, for example, a rising urine albumin can signal the onset of diabetic nephropathy, allowing for early intervention. Moreover, albuminuria is not only a marker of renal disease but also a well-recognized risk factor for cardiovascular disease – higher urine albumin excretion is associated with greater risk of heart disease and mortality in people with and without diabetes. In other words, the greater the albumin leakage, the worse the cardiovascular and kidney prognosis. If urine albumin is too high, medications like ACE inhibitors and ARBs may be recommended to protect the kidneys and reduce cardiovascular risk.

Albuminuria is detected using the ACR, which standardizes urinary albumin excretion with creatinine excretion. Urine albumin should not be used in isolation to guide clinical management.