How often to monitor Albumin-to-Creatinine Ratio (ACR) in Chronic Kidney Disease (CKD)?

From the Guidelines

Monitoring albumin-to-creatinine ratio (ACR) in chronic kidney disease (CKD) should typically be done at least annually, with more frequent assessments for individuals at higher risk of CKD progression, as recommended by the KDIGO 2024 clinical practice guideline 1. The frequency of ACR monitoring may vary depending on several factors, including the etiology of disease, therapeutic regimen, and baseline UACR level, as emphasized by the KDOQI Work Group 1. Key considerations for ACR monitoring include:

• Assessing albuminuria and GFR at least annually in people with CKD, with more frequent assessments for those at higher risk of progression 1
• Evaluating changes in eGFR and UACR that exceed expected variability, such as a change in eGFR of >20% or a doubling of the UACR 1
• Individualizing the frequency of UACR testing based on factors such as disease etiology, therapeutic regimen, and baseline UACR level 1
• Considering more frequent monitoring, such as every 3-6 months, for patients with established albuminuria, recent medication changes, or severe albuminuria (ACR >300 mg/g) 1 ACR monitoring is crucial for tracking kidney disease progression, assessing response to treatments, and guiding management decisions, as it helps identify worsening kidney damage or improvement with therapy 1. First morning void urine samples are preferred for consistency, and results should be interpreted in the context of other kidney function markers like estimated glomerular filtration rate (eGFR) 1. Temporary factors like fever, exercise, or urinary tract infections can affect results, so consistent testing conditions are essential for accurate trend assessment 1.

From the Research

Monitoring Albumin-to-Creatinine Ratio (ACR) in Chronic Kidney Disease (CKD)

• The frequency of monitoring ACR in CKD is not explicitly stated in the provided studies, but it can be inferred from the recommendations for screening and diagnosis of CKD.
• According to the study 2, screening for CKD is recommended using the spot urine albumin-to-creatinine ratio and estimated glomerular filtration rate in all patients with type 2 diabetes at the time of diagnosis, and at least annually thereafter.
• The study 3 also suggests that annual screening is necessary to diagnose CKD, but it does not provide specific guidance on the frequency of monitoring ACR.
• The study 4 measures UACR once and finds that UACR is a significant predictor of CKD progression, but it does not provide information on the optimal frequency of monitoring.
• The study 5 compares different urinary indices for albuminuria and proteinuria, but it does not address the frequency of monitoring ACR.
• The study 6 analyzes the effect of different treatments on CKD progression, but it does not provide guidance on the frequency of monitoring ACR.

Factors Influencing CKD Progression

• The study 4 finds that UACR is a significant predictor of CKD progression, and that the risk of progression increases linearly with higher levels of albuminuria.
• The study 6 finds that treatment with ACEI or ARB has a superior effect on slowing kidney disease progression and reducing proteinuria compared to no ACEI or ARB treatment.
• The study 3 identifies patient-level factors associated with nonconcordance with guideline-recommended CKD screening and treatment, including Hispanic ethnicity and lack of comorbidities.
• The study 5 finds that ePER and eAER are superior to PCR and ACR in quantifying daily proteinuria and albuminuria.
• The study 2 emphasizes the importance of early screening and diagnosis of CKD in patients with type 2 diabetes, and recommends good glycemic and blood pressure control and the use of medications that are kidney protective.