Diabetic Nephropathy

Progressive kidney disease caused by damage to the capillaries in the glomeruli

Pathophysiology

  • It is characterised by proteinuria and diffuse scarring of the glomeruli
  • Also known as Kimmelsteil-Wilson Syndrome or Nodular Glomerulosclerosis

Investigations

  1. If ACR <30 or PCR <50 = microalbuminuria
    1. Repeat twice as false positive readings are common
    2. Established microalbuminuria if 2/3 positive
    3. Microalbuminuria will not show up as protein++ on urine dipstick
  1. If ACR >30 or PCR >50 = proteinuria (overt nephropathy)
    1. Repeat on EMU
    2. Proteinuria will show up on a urine dipstick

Management

  • Presence of microalbuminuria requires treatment with ACEi/ARB
    • Dilate renal arterioles so decrease filtration pressure → decrease proteinuria (also decreases GFR - allow up to 20% deterioration in GFR)
  • Diabetic patients with microalbuminuria should be started on an SGLT2i (irrespective of HBA1c)
  • Manage other vascular complications e.g. discourage smoking, assess fasting lipid profile, screen for cardiovascular disease and hypertension
    • Target BP is <140/80 mmHg for all patients with diabetes
  • Aggressive treatment of blood pressure, glycaemia and use of ACEi/AGLT2i can prevent decline in renal function

Prevention

  • Good glycaemic control (53mmol/mol) in patients with T2DM should be maintained to reduce the risk of developing diabetic neuropathy (depending on age and other risk factors

Complications

  • Development of hypertension
  • Relentless decline in renal function
    • Reduction in GFR of 1ml/min/month if untreated
  • Accelerated vascular disease
  • Microalbuminuria is a sign of damage to the glomeruli causing protein leak
    • Marker of 'high risk' of other vascular problems