The REIN study, a multicenter randomized, double-blind parallel group, placebo-controlled study aimed at assessing the effect of treatment with ramipril on the rate of decline of glomerular function rate (GFR) in 352 normotensive or hypertensive patients (18-70 years old) suffering from mild (i. e. mean urinary protein excretion > 1 and < 3 g/ 24 h) or severe proteinuria (≥ 3 g/ 24 h) due to chronic non-diabetic nephropathy.