Albumin-Creatinine Ratio Guidelines

Definition and Interpretation

• The American Journal of Kidney Diseases and Diabetes Care recommend that a normal albumin-to-creatinine ratio (ACR) is ≤30 mg/g creatinine, with values >30 mg/g indicating abnormal albuminuria that warrants further evaluation 1, 2, 3
• The National Kidney Foundation and American Diabetes Association define the following ACR thresholds: Normal to mildly increased (A1): <30 mg/g creatinine, Moderately increased albuminuria (A2): 30-299 mg/g creatinine, and Severely increased albuminuria (A3): ≥300 mg/g creatinine 2

Measurement and Reporting

• The American College of Physicians and Annals of Internal Medicine recommend using spot urine albumin-to-creatinine ratio rather than timed collections, as this method is more convenient and correlates well with 24-hour measurements 1, 4
• The American Academy of Pediatrics recommends that the first morning void is preferred for children and adolescents to avoid orthostatic proteinuria, though random specimens are acceptable for adults 1, 4
• Laboratories should report results as milligrams of albumin per gram of creatinine (mg/g) 1

Confirmation and Screening

• The American Journal of Kidney Diseases and Diabetes Care recommend that a single elevated value should not be considered diagnostic - persistent albuminuria must be confirmed before making treatment decisions 1, 2
• The American Diabetes Association recommends confirming values >30 mg/g with 2 of 3 positive samples collected over 3-6 months, particularly in patients with diabetes 1, 2
• The National Kidney Foundation recommends annual screening for all adults with diabetes, hypertension, or family history of chronic kidney disease 1, 2
• The American Diabetes Association recommends that if ACR is >30 mg/g or eGFR <60 mL/min/1.73 m², repeat testing every 6 months to assess progression and treatment response 2, 3