What does an albumin (Albumin)/creatinine (Creatinine) ratio of 79 indicate?

From the Guidelines

An albumin/creatinine ratio of 79 indicates moderately increased albuminuria, which is an early sign of kidney damage and associated with increased risk of progressive kidney disease and cardiovascular complications. This level falls between 30-300 mg/g, suggesting that the kidneys are allowing small amounts of albumin protein to leak into the urine when they should be retaining it 1. The finding warrants medical attention and follow-up testing to confirm the result, as transient elevations can occur due to fever, exercise, or urinary tract infections.

Key Considerations

• The albumin/creatinine ratio is a continuous marker for cardiovascular event risk at all levels of kidney function, and the risk starts at values consistently above 30 mg/g 1.
• Management typically includes blood pressure control (often with ACE inhibitors or ARBs), blood sugar optimization if diabetic, dietary sodium restriction, and lifestyle modifications such as weight loss if overweight, smoking cessation, and regular exercise.
• The underlying cause of the albuminuria should be identified and treated, as conditions like diabetes and hypertension are common contributors to kidney damage.
• Regular monitoring of kidney function and albuminuria is essential to track disease progression and treatment effectiveness, with the frequency of monitoring depending on the severity of CKD and the risk for progression 1.

Clinical Implications

• The use of point-of-care testing may facilitate access to earlier diagnosis and care, especially in rural and remote locations, and should include the capacity for generating creatinine-based eGFR equations 1.
• Understanding the sources of both analytical and biological variability in urine albumin or protein measures is important for the interpretation of fluctuations in urine ACR.
• Clinicians should appreciate the differences between albuminuria and proteinuria, as they are not the same, and albuminuria measurements may not be available in all regions 1.

From the Research

Understanding Albumin/Creatinine Ratio

• The albumin/creatinine ratio (ACR) is a test used to assess kidney damage and diagnose chronic kidney disease (CKD) 2, 3, 4, 5, 6.
• ACR measures the amount of albumin (a protein) in the urine compared to the amount of creatinine (a waste product) 5.
• The ratio is usually expressed in milligrams of albumin per gram of creatinine (mg/g) or milligrams per millimole (mg/mmol) 5.

Interpreting ACR Results

• An ACR of 79 mg/g is considered abnormal and may indicate kidney damage or disease 3, 4.
• The American Diabetes Association recommends the following ACR categories:
  • Normal: <30 mg/g
  • Microalbuminuria: 30-300 mg/g
  • Macroalbuminuria: >300 mg/g 2.
• However, the study by 3 suggests that even lower levels of albuminuria (<30 mg/g) can be associated with an increased risk of CKD progression.

Comparison with Other Tests

• The urine dipstick test is a widely used screening tool for albuminuria, but it has poor sensitivity and high false-discovery rates compared to ACR 4.
• The protein-creatinine ratio (PCR) is another test that can be used to quantify proteinuria, and it has been shown to be more sensitive than ACR in predicting clinically relevant proteinuria 5.
• Calculated ACR from urine dipstick protein or PCR can be used to predict kidney failure and death in people with CKD, but its performance may vary depending on the method used 6.

Clinical Implications

• An abnormal ACR result, such as 79 mg/g, should be confirmed with repeat testing and evaluated in the context of other clinical factors, such as estimated glomerular filtration rate (eGFR) and presence of diabetes or cardiovascular disease 2, 3, 6.
• Patients with CKD and abnormal ACR results should be monitored regularly for progression of kidney disease and cardiovascular risk factors 2, 3.