Diabetic Nephropathy (Diabetic Kidney Disease) is a progressive microvascular kidney complication caused by long-standing high blood sugar levels in diabetes. It damages the tiny filtering units of the kidneys (glomeruli), leading to protein leaking into urine (proteinuria/albuminuria) and gradual kidney failure.
Causes & Risk Factors
- Chronic Hyperglycemia: High blood sugar damages renal blood vessels and glomerular filtration barriers.
- Uncontrolled Hypertension: Elevated systemic blood pressure increases intra-glomerular pressure and strain.
- Dyslipidemia: Elevated cholesterol accelerates vascular sclerosis in renal tissue.
- Genetics & Family History: Family history of kidney disease or hypertension.
- Smoking & Excessive Alcohol: Accelerates renal function decline.
- Obesity & Sedentary Lifestyle: Increases metabolic hyperfiltration load on kidneys.
Symptoms Across Stages
- Early Stages: Usually asymptomatic ("silent progression"). Microalbuminuria detectable only via lab tests.
- Later Stages: Foamy or frothy urine (due to heavy protein leakage), swelling (edema) in feet, ankles, hands, and eyes; frequent nighttime urination (nocturia), persistent fatigue, nausea/vomiting, loss of appetite, shortness of breath (fluid in lungs), and worsening hypertension.
Stages of Diabetic Nephropathy
| Stage | eGFR (Kidney Function) | Clinical Symptoms & Characteristics |
|---|---|---|
| Stage 1 | > 90 mL/min | Normal or high eGFR, hyperfiltration, microalbuminuria may begin. |
| Stage 2 | 60–89 mL/min | Mild kidney damage, persistent protein in urine, asymptomatic. |
| Stage 3 | 30–59 mL/min | Moderate kidney damage, mild swelling, rising BP, fatigue. |
| Stage 4 | 15–29 mL/min | Severe kidney damage, pronounced edema, anemia, nausea. |
| Stage 5 | < 15 mL/min | End-Stage Kidney Disease (ESKD); dialysis or transplant required. |
Diagnostic Workup
- Urine Albumin-to-Creatinine Ratio (UACR): Detects microalbuminuria (> 30 mg/g).
- Serum Creatinine & eGFR Blood Test: Calculates precise filtration capacity.
- Blood Pressure Monitoring: High BP accelerates glomerulosclerosis.
- Renal Ultrasound / Biopsy: Rules out non-diabetic kidney pathologies if atypical presentation occurs.
Treatment & Prevention Strategy
- Glycemic Control: Maintain target HbA1c < 7.0%.
- Renoprotective Blood Pressure Medications: ACE Inhibitors (e.g., Lisinopril) or ARBs (e.g., Losartan) reduce intra-glomerular pressure and reduce proteinuria.
- SGLT2 Inhibitor Therapy: Significantly slows CKD progression in diabetic patients.
- Dietary Adjustments: Low-protein diet (reduces renal workload), low-sodium intake (< 2g/day) to control edema and BP.
- Avoid Nephrotoxic Drugs: Avoid NSAIDs (such as Ibuprofen, Naproxen) and iodinated radiocontrast agents.
- Statin Lipid Control & Smoking Cessation: Protects systemic vascular health.
