From the Guidelines
Chronic kidney disease (CKD) is defined as kidney damage or a glomerular filtration rate <60 mL/min/1.73m2 for three months or longer, where kidney damage is defined as pathologic abnormalities or markers of damage, including abnormalities in blood or urine tests or imaging studies. This definition, as outlined in the National Kidney Foundation Kidney Disease Outcomes Quality Initiative for CKD 1, emphasizes the importance of both structural and functional abnormalities in the diagnosis of CKD. Key aspects of CKD definition include:
- Kidney damage, which can be indicated by pathologic abnormalities or markers of damage
- Glomerular filtration rate (GFR) below 60 mL/min/1.73m² for at least 3 months
- The presence of these conditions for more than 3 months, which distinguishes CKD from acute kidney injuries or transient conditions. The implications of CKD on health are significant, and its diagnosis and staging are crucial for guiding treatment approaches and predicting outcomes, as evidenced by guidelines such as those found in the Kidney International Supplements 1.
From the Research
Definition of Chronic Kidney Disease (CKD)
- CKD is defined as a glomerular filtration rate (GFR) less than 60 mL/min/1.73 m2 or persistent evidence of kidney damage on imaging, biopsy, or urinalysis that persists for longer than 3 months 2, 3, 4.
- Kidney damage can be ascertained by the presence of albuminuria, defined as albumin-to-creatinine ratio >30 mg/g in two of three spot urine specimens 3.
- The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is the most accurate creatinine-based method for estimating GFR in routine practice 2, 5.
Diagnosis and Staging of CKD
- Diagnosis is commonly made after chance findings from screening tests (urinary dipstick or blood tests), or when symptoms become severe 4.
- The best available indicator of overall kidney function is GFR, which is measured either via exogenous markers or estimated using equations 4, 5.
- Presence of proteinuria is associated with increased risk of progression of CKD and death 4, 6.
- CKD is classified into stages based on estimated GFR, degree of proteinuria, and the cause 2, 3.
Importance of Early Detection and Management
- Early detection and management of CKD are crucial to slow disease progression and reduce the risk of cardiovascular disease and premature death 2, 4, 5.
- Screening should be considered if patients are at high risk of CKD, such as those with diabetes, hypertension, cardiovascular disease, or family history of kidney failure 2.