From the Guidelines
A normal albumin to creatinine ratio (ACR) of 19 mg/g indicates the absence of significant kidney damage and suggests normal kidney function. The ACR measures the amount of albumin (a protein) in the urine relative to creatinine, with normal values being less than 30 mg/g, as defined by recent guidelines 1. This normal result is clinically significant because it suggests the kidneys are effectively filtering blood without allowing excessive protein leakage into the urine. Albumin in urine is an early marker of kidney damage, particularly in conditions like diabetes and hypertension, so a normal ACR helps rule out early diabetic nephropathy and other kidney diseases.
Some key points to consider:
- The ACR is a useful screening tool for kidney disease, and a normal result can help identify individuals who are at low risk of progressive kidney disease 1.
- However, it's essential to interpret the ACR alongside other tests like estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), and serum creatinine for a comprehensive assessment of kidney function.
- Regular monitoring is recommended for high-risk patients (those with diabetes, hypertension, or family history of kidney disease) as kidney function can change over time 1.
- The physiological basis for this test is that healthy glomeruli (kidney filtering units) have intact filtration barriers that prevent larger proteins like albumin from passing into the urine, so minimal albumin excretion reflects properly functioning glomerular membranes.
In terms of clinical management, the presence of a normal ACR does not necessarily preclude the need for ongoing monitoring or treatment of underlying conditions that may affect kidney function. For example, patients with hypertension or diabetes may still require regular monitoring of their kidney function and adjustment of their treatment plans to slow the progression of kidney disease 1. Overall, a normal ACR is a reassuring sign, but it should be considered in the context of the individual's overall clinical picture and risk factors for kidney disease.
From the Research
Clinical Significance of Normal Albumin to Creatinine Ratio
- A normal albumin to creatinine (ACR) ratio is generally considered to be between 0-29 mg/g creatinine 2, 3.
- The clinical significance of a normal ACR ratio in terms of kidney function is that it indicates a low risk of kidney damage or disease 2.
- However, studies have shown that even a normal ACR ratio can be associated with an increased risk of cardiovascular and renal outcomes, particularly in high-risk patients such as those with diabetes, hypertension, and chronic kidney disease 2, 3.
Association with Cardiovascular and Renal Outcomes
- A study published in 2021 found that a higher ACR ratio, even within the normal range, was associated with an increased risk of all-cause and cardiovascular mortality 3.
- Another study published in 2025 found that an ACR ratio within the normal range was associated with continuous glucose monitoring-derived metrics in children and adolescents with type 1 diabetes, suggesting a potential link between albuminuria and glucose control 4.
Analytical Methods and Impact on ACR
- A study published in 2022 compared two analytical methods for quantifying urinary albumin and creatinine and found significant interassay differences, which may affect ACR stratification 5.
- The study highlighted the importance of using standardized analytical methods to ensure accurate ACR results and to minimize the risk of misclassifying patients with kidney disease 5.
Kidney Disease Progression
- A study published in 2010 discussed the frequency of diabetes, hypertension, and chronic kidney disease according to albumin-to-creatinine ratio and estimated glomerular filtration rate (eGFR) 6.
- The study emphasized the importance of monitoring ACR and eGFR to track kidney disease progression and to identify patients at high risk of adverse outcomes 6.