Overview
Definition
Structural or functional abnormalities of the kidneys, or a Glomerular Filtration Rate (GFR) < 60 mL/min/1.73m², present for > 3 months.
Epidemiology
Affects ~15% of the US adult population. Prevalence increases with age, diabetes, and hypertension.
Etiology & Risk Factors
- Diabetes Mellitus (Diabetic Nephropathy - most common cause)
- Hypertension (Hypertensive nephrosclerosis - second most common)
- Glomerulonephritis
- Polycystic Kidney Disease (PKD)
Clinical Symptoms
- Often asymptomatic in early stages (Stages 1-3)
- Advanced stages (Stages 4-5): Fatigue, edema, nausea, pruritus (uremic frost), restless legs
- Uremia: Encephalopathy (confusion, asterixis), Pericarditis (friction rub)
Clinical Approach
Diagnosis
- eGFR calculation based on serum creatinine, age, sex, and race
- Urine Albumin-to-Creatinine Ratio (UACR): > 30 mg/g indicates albuminuria (early sign of diabetic nephropathy)
- Renal Ultrasound: Typically shows small, echogenic kidneys (except in PKD or diabetic nephropathy where they may be large/normal)
Management
- Treat underlying cause: Strict BP and blood glucose control
- ACE inhibitors or ARBs (to reduce proteinuria and slow progression)
- SGLT2 Inhibitors (e.g., Dapagliflozin) have proven extreme benefit in slowing CKD progression
- Manage complications: Erythropoietin (for anemia), Phosphate binders (for hyperphosphatemia), Vitamin D analogs
Complications
- End-Stage Renal Disease (ESRD) requiring dialysis or transplant
- Cardiovascular disease (leading cause of death in CKD patients)
- Renal osteodystrophy (bone disease)
- Severe hyperkalemia