What is the Difference Between Albuminuria and Proteinuria?

The main difference between albuminuria and proteinuria lies in the specific proteins being measured in the urine. Here are the key distinctions:

• Albuminuria: This refers to the presence of albumin, a type of plasma protein, in the urine. Albumin is not usually found in the urine, and its presence indicates kidney damage, specifically when the damage occurs in the glomerulus (the kidney's filter). Albuminuria is considered the gold standard for quantifying urine protein and is associated with all-cause mortality, kidney disease progression, kidney failure, and cardiovascular-related deaths.
• Proteinuria: This indicates an elevated presence of protein in the urine, with normal excretion being less than 150 mg/d. Proteinuria includes both albuminuria and non-albumin proteinuria, but albumin is usually the largest contributor to proteinuria. Dip-stick proteinuria correlates poorly with albumin-to-creatinine ratio (ACR), while protein-to-creatinine ratio (PCR) correlates reasonably well with ACR.

Both albuminuria and proteinuria are important disease markers of chronic kidney disease (CKD). However, recent findings and guidelines have led to albuminuria being considered the gold standard for quantifying urine protein.

Comparative Table: Albuminuria vs Proteinuria

The key difference between albuminuria and proteinuria is that albuminuria is a medical condition occurring due to the abnormal loss of albumin in the urine, while proteinuria is a medical condition characterized by the presence of elevated levels of proteins in the urine. Here is a table summarizing the differences between albuminuria and proteinuria:

Both albuminuria and proteinuria are important disease markers of chronic kidney disease (CKD) and are associated with the rapid progression of CKD to end-stage renal disease. They can be caused due to common factors such as diabetes, high blood pressure, infection, and others.