From the Guidelines
Kidney disease progresses through five distinct stages, each characterized by declining kidney function measured by glomerular filtration rate (GFR), with the most recent guidelines from 2009 suggesting a focus on patient prognosis 1.
Stages of Kidney Disease
The stages of kidney disease are defined as follows:
- Stage 1: Normal kidney function (GFR ≥90 ml/min) with signs of kidney damage like protein in urine.
- Stage 2: Mild decrease in kidney function (GFR 60-89 ml/min) with continued evidence of kidney damage.
- Stage 3: Moderate kidney damage, divided into 3a (GFR 45-59 ml/min) and 3b (GFR 30-44 ml/min), with potential complications like high blood pressure and anemia.
- Stage 4: Severe kidney damage (GFR 15-29 ml/min) with more pronounced symptoms and complications.
- Stage 5: Kidney failure or end-stage renal disease (GFR <15 ml/min), requiring dialysis or kidney transplantation for survival.
Importance of Early Detection and Treatment
Early detection through regular blood and urine tests is crucial, especially for those with risk factors like diabetes, hypertension, or family history of kidney disease, as it allows for timely intervention to slow disease progression 1. Treatment focuses on slowing progression through blood pressure control with medications like ACE inhibitors or ARBs, blood sugar management for diabetics, dietary modifications limiting sodium, protein, and potassium, and lifestyle changes including smoking cessation and regular exercise.
Recent Guidelines and Recommendations
The most recent guidelines from 2009 emphasize the importance of considering patient prognosis in the classification and management of chronic kidney disease 1. This approach highlights the need for a more personalized and prognostic-based approach to managing kidney disease, rather than solely relying on the traditional staging system.
From the Research
Stages of Kidney Disease
The stages of kidney disease are classified based on the glomerular filtration rate (GFR) as recommended by many professional guidelines 2, 3. The five stages of kidney disease are:
- Stage 1: Kidney damage with normal or high GFR
- Stage 2: Kidney damage with a mild decrease in GFR
- Stage 3: Moderate decrease in GFR
- Stage 4: Severe decrease in GFR
- Stage 5: Kidney failure, requiring dialysis or transplantation
Classification of Kidney Disease
Kidney disease is defined as kidney damage or GFR <60 mL/min/1.73 m(2) for 3 months or more, irrespective of cause 3. 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.
Diagnosis and Management
The development of formula-based calculation of estimated GFR (eGFR) has offered a practical and easy approach for converting serum creatinine value into GFR result, taking into consideration patient's age, sex, ethnicity, and weight (depending on equation type) 2. The commonly used equations include Cockcroft and Gault, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI).
Treatment and Progression
Pharmacologic interventions, such as ACE-inhibitors and angiotensin receptor blockers, can slow chronic kidney disease progression, but their value in advanced kidney disease is unknown 4. The use of high doses of ACEI/ARB and their up-titration in patients with heart failure and chronic kidney disease may be appropriate, provided that the patient is adequately monitored 5.