Diabetic nephropathy

Related Subjects: Type 1 DM | Type 2 DM | Diabetes in Pregnancy | HbA1c | Diabetic Ketoacidosis (DKA) Adults | Hyperglycaemic Hyperosmolar State (HHS) | Diabetic Nephropathy | Diabetic Retinopathy | Diabetic Neuropathy | Diabetic Amyotrophy | Maturity Onset Diabetes of the Young (MODY) | Diabetes: Complications | Analgesic NephropathyIgA Nephropathy (Berger's disease)HIV associated nephropathy (HIVAN)Balkan endemic nephropathy (BEN)

🩺 Diabetic Nephropathy is the most common cause of end-stage renal failure (ESRF) in the UK. It is defined by nodular diabetic glomerulosclerosis with thickened basement membranes, mesangial expansion, and the pathognomonic Kimmelstiel–Wilson lesion. 💡 Early detection + tight risk-factor control can dramatically slow progression.

🧾 About

• A microvascular complication of both type 1 and type 2 diabetes.
• Up to 60% of type 1 diabetics develop it after 30 years’ disease duration.
• Earliest sign: Microalbuminuria (30–300 mg/24 hr).
• Accelerated by hypertension and poor glycaemic control.

⚠️ Effects

• Glomerular sclerosis → declining GFR 📉
• Renal papillary necrosis 🔥
• Progression to chronic kidney disease (CKD)
• Recurrent UTIs 🦠
• Diabetic arteriolar disease 🩸
• Hyporeninaemic hypoaldosteronism → hyperkalaemia ⚡

🚩 Red Flags (think alternative diagnosis)

• ❌ Absence of diabetic retinopathy
• ❌ Persistent haematuria / red cell casts
• ❌ Renal impairment without proteinuria
• ❌ Rapid unexplained decline in renal function

Microalbuminuria: ACR >3 mg/mmol but negative dipstick. Overt nephropathy: ACR >30 mg/mmol.

🔍 Investigations

• Urine ACR (early morning):   • >3 mg/mmol → microalbuminuria   • >30 mg/mmol → overt nephropathy
• U&E + creatinine: calculate eGFR.
• CKD diagnosis: eGFR <60 mL/min/1.73m² for ≥3 months OR persistent ACR >3 mg/mmol.

🧬 Pathology

• Kimmelstiel–Wilson nodules 🌰
• Nodular glomerulosclerosis
• Thickened GBM
• Mesangial expansion

📉 Natural History

• Hyperfiltration (early) → Microalbuminuria
• Overt proteinuria → Declining GFR
• End-stage renal failure (ESRF)

💊 Management of CKD in Diabetes

• 📅 Annual screening: urine ACR + eGFR
• 🩸 BP target: <130/80 mmHg (ACEi/ARB first-line)
• 🧃 Glycaemic control: optimise HbA1c
• 💊 Lipid control: Atorvastatin 20 mg OD
• 🚭 Stop smoking
• 🔎 Refer nephrology if:   • ACR >7 mg/mmol, OR   • GFR decline >5 mL/min/1.73m²/year
• 🩺 Advanced disease → dialysis or renal ± pancreatic transplantation
• 📖 Patient education: sick-day rules (withhold ACEi/ARB, NSAIDs, metformin, diuretics during illness to prevent AKI)

💡 Clinical Pearls

• 🌟 Microalbuminuria precedes proteinuria – catch it early
• 👁 Always check for diabetic retinopathy → absence suggests alternative pathology
• 💊 ACEi/ARBs not only reduce BP but slow nephropathy progression

📚 References

• NICE – Diabetic complications