Time course of antiproteinuric effect of aliskiren in arterial hypertension associated with type 2 diabetes and microalbuminuria

Objective: The aim was to compare the antiproteinuric effect of aliskiren and ramipril in hypertensive patients with type 2 diabetes and microalbuminuria. Research design and methods: A total of 138 patients were treated with aliskiren 300 mg/day or ramipril 10 mg/day for 12 weeks and checked after 1, 2, 4, 8 and 12 weeks and 2 and 4 weeks after treatment withdrawal. Main outcome measures: Clinic and ambulatory BP, urinary albumin excretion rate (UAER) and plasma aldosterone were measured. Results: Both aliskiren and ramipril induced a similar lowering in clinic and ambulatory BP (p <0.001 vs baseline). However, such a lowering persisted longer after stopping aliskiren than after stopping ramipril regimen. Both treatments reduced UAER, but the decrease in UAER associated with aliskiren was more pronounced, the difference vs ramipril being maximal at week 12 (-42 vs -15%, p <0.01). Two weeks after stopping therapy, UAER remained below baseline values with aliskiren, but not in the ramipril group. Plasma aldosterone decreased in the aliskiren group, whereas in the ramipril group it decreased until week 8 and thereafter increased toward baseline values. Conclusions: Aliskiren has a greater and more prolonged antiproteinuric effect than R; it might partly be related to a higher degree of intrarenal renin-angiotensin-aldosterone system blockade.