SM 207a - Diabetic Nephropathy

Question 1

What functional changes occur during the hyperfiltration (silent) phase of diabetic nephropathy?

Answer 1

• Increased GFR (but this is usually not detected in labs)
• Increased kidney size
• Glomerular hypertrophy (without proliferation of cells)
• Glomerular basement membrane thickening
• Usually occurs for 5-10 years

Question 2

What are the major strategies for treatment and progression prevention for diabetic nephropathy?

Answer 2

• Tight glycemic control
  
  • Reduces microalbuminuria, but may not slow GFR decline
• Treat hypertension
  
  • Perhaps the most important risk factor for the progressive decline in GFR in diabetes
  • Goal is <140/90, but <130/80 is probably better
  • Use ACEI or ARB
• SGLT-2 inhibitors
  
  • Inhibt Na+ and glucose uptake in the PCT
  • -> Urinary glucose loss
  • -> Prevent activation of RAAs

Question 3

What is the main cause of decreased GFR in patients with diabetic neprophathy?

Answer 3

Mesangial matrix expansion

• Impinges on capillary loops
• Obliterates the surface area available for filtration
• -> Tubulointerstitial fibrosis
  
  • -> Nephron loss