From the Guidelines
Yes, persistent albuminuria for ≥3 months is indeed a diagnostic criterion for chronic kidney disease (CKD), even with normal glomerular filtration rate (GFR). According to the most recent and highest quality study 1, CKD screening and risk stratification must consist of a dual assessment of estimated glomerular filtration rate (eGFR) and albuminuria (UACR). The presence and severity of albuminuria guides the use and dosage of treatments and is crucial for effective risk stratification of persons with CKD.
Key Points to Consider
- Persistent albuminuria is defined as an albumin-to-creatinine ratio (ACR) of ≥30 mg/g in at least two of three urine specimens 1.
- Albuminuria represents kidney damage and is a strong predictor of progression to more advanced kidney disease, cardiovascular events, and mortality, even when GFR is normal.
- Patients with normal GFR but persistent albuminuria are classified as having Stage 1 CKD if GFR is ≥90 mL/min/1.73m² or Stage 2 CKD if GFR is between 60-89 mL/min/1.73m².
- These patients should be monitored regularly with blood pressure measurements, urinalysis, and GFR estimation to track disease progression and implement appropriate interventions.
Management and Monitoring
The management of CKD involves monitoring and interventions to slow disease progression and reduce the risk of cardiovascular events. Monitoring should include regular assessments of eGFR and albuminuria, as well as blood pressure measurements and urinalysis. The frequency of monitoring will depend on the severity of CKD and the risk for progression, with more frequent monitoring recommended for those with higher levels of albuminuria or lower eGFR 1.
Importance of Early Identification and Intervention
Early identification and intervention of CKD are critical to prevent progression to more advanced kidney disease and reduce the risk of cardiovascular events and mortality. Assessing both kidney function by eGFR and kidney damage by measuring albuminuria are critical for effective risk stratification of persons with CKD 1. By prioritizing the monitoring and management of CKD, clinicians can improve outcomes and reduce the burden of this disease on patients and healthcare systems.
From the Research
Diagnostic Criteria for Chronic Kidney Disease
- Persistent albuminuria for ≥3 months is a diagnostic criterion for chronic kidney disease, even with normal GFR, as supported by various studies 2, 3, 4.
- Albuminuria is an important predictor of both cardiovascular and kidney outcomes in chronic kidney disease, independent of eGFR 2.
- Many individuals with normal eGFR have albuminuria, highlighting the need for albuminuria measurement in screening for chronic kidney disease 2.
Albuminuria Assessment
- Albuminuria assessment is now integrated into CKD staging, cardiovascular risk prediction models, and therapy selection 3.
- The predictive value of albuminuria for kidney and cardiovascular outcomes is reinforced by advances in measurement techniques and evidence from large-scale studies 3.
- Albuminuria may be a marker of both glomerular and tubular damage, whereas eGFR is merely a marker of glomerular damage 2.
Clinical Implications
- Screening for chronic kidney disease should at least include measurement of albuminuria, in addition to eGFR 2, 4.
- Future studies should consider whether the inclusion of other markers of tubular damage will further improve the ability to predict outcomes in patients with chronic kidney disease 2.
- Albuminuria is a major risk factor for chronic kidney disease progression, especially when categorized as moderate or severe 5.