Micro vs Macro Albuminuria

Macroalbuminuria and microalbuminuria refer to the amount of albumin, a type of protein, excreted in the urine. The ACR reference ranges differ slightly between males and females due to males having a higher muscle mass, which leads in turn to a higher creatinine and a lower ACR.

  • Microalbuminuria:
    • Typically defined as a urinary albumin excretion rate (uAER) of 30-300 mg/24h.
    • Another commonly used measure is the albumin-to-creatinine ratio (ACR) in a random spot urine sample. For microalbuminuria, the ACR typically ranges from:
      • 2.5 to 25 mg/mmol in males.
      • 3.5 to 35 mg/mmol in females.
  • Macroalbuminuria (or overt albuminuria):
    • Defined as a uAER of more than 300 mg/24h.
    • In terms of ACR in a random spot urine sample:
      • > 25 mg/mmol in males.
      • > 35 mg/mmol in females.

The presence of microalbuminuria can be an early indicator of kidney damage, particularly in people with diabetes. If left unaddressed, microalbuminuria can progress to macroalbuminuria, which is associated with a higher risk of cardiovascular events and more advanced kidney disease. Regular screening and appropriate management are crucial to prevent the progression of kidney disease and related complications.