Diabetic nephropathy: stages

Diabetic nephropathy may be classified as occurring in five stages*:

Stage 1
hyperfiltration: increase in GFR
may be reversible

Stage 2 (silent or latent phase)
most patients do not develop microalbuminuria for 10 years
GFR remains elevated

Stage 3 (incipient nephropathy)
microalbuminuria (albumin excretion of 30 - 300 mg/day, dipstick negative)

Stage 4 (overt nephropathy)
persistent proteinuria (albumin excretion > 300 mg/day, dipstick positive)
hypertension is present in most patients
histology shows diffuse glomerulosclerosis and focal glomerulosclerosis (Kimmelstiel-Wilson nodules)

Stage 5
end-stage renal disease, GFR typically < 10ml/min
renal replacement therapy needed

The timeline given here is for type 1 diabetics. Patients with type 2 diabetes mellitus (T2DM) progress through similar stages but in a different timescale - some T2DM patients may progress quickly to the later stages