From the Guidelines
The ACR, or Albumin-to-Creatinine Ratio, is used to assess kidney damage and predict renal and cardiovascular outcomes in patients with chronic kidney disease (CKD) 1. The ACR is a continuous measurement, and differences within the normal and abnormal ranges are associated with renal and cardiovascular outcomes.
- A normal UACR is defined as <30 mg/g Cr, and high urinary albumin excretion is defined as ≥30 mg/g Cr.
- However, due to high biological variability of >20% between measurements in urinary albumin excretion, two of three specimens of UACR collected within a 3- to 6-month period should be abnormal before considering a patient to have high or very high albuminuria 1. The ACR is also used in conjunction with the estimated Glomerular Filtration Rate (eGFR) to assess kidney function, with an eGFR persistently <60 mL/min/1.73 m2 in concert with a urine albumin value of >30 mg/g creatinine considered abnormal 1. The use of ACR is recommended for evaluation of proteinuria in preference to urinary total protein, as albumin is the most important protein lost in the urine in most cases of CKD, and urinary ACR accurately predicts kidney and cardiovascular risks 1.
From the Research
Uses of ACR
- The albumin-to-creatinine ratio (ACR) is used to evaluate chronic kidney disease (CKD) and predict the risk of kidney failure and death 2, 3, 4, 5.
- ACR is also used to diagnose and manage diabetic kidney disease (DKD) 4.
- In addition to its use in nephrology, ACR can also refer to the American College of Radiology (ACR) Appropriateness Criteria, which is a guideline for selecting appropriate imaging modalities in various clinical scenarios 6.
Clinical Applications
- ACR is used to quantify proteinuria and detect kidney damage 2, 3, 4, 5.
- It is also used to monitor the progression of CKD and adjust treatment accordingly 2, 3, 4.
- ACR point-of-care testing can aid in the diagnosis and management of DKD, allowing for timely interventions and improved patient outcomes 4.