Impact of telmisartan versus ramipril on renal endothelial function in patients with hypertension and type 2 diabetes.
OBJECTIVE
One of the earliest signs of vascular change is endothelial dysfunction, which is also known to provoke albuminuria and to predict cardiovascular prognosis. The aim of this study was to analyze the effects of renin-angiotensin system (RAS) blockade on renal endothelial function.


METHODS
In a multicenter, prospective, double-blind, forced-titration, randomized study, 96 patients with type 2 diabetes, hypertension, glomerular filtration rate >80 ml/min, and normo- or microalbuminuria were treated once daily with 40/80 mg telmisartan or 5/10 mg ramipril for 9 weeks.


RESULTS
The mean +/- SE fall in renal plasma flow (RPF) in response to intravenous N(G)-monomethyl-L-arginine (L-NMMA), reflecting the magnitude of nitric oxide (NO) activity, increased with telmisartan from 71.9 +/- 9.0 ml/min before therapy to 105.2 +/- 9.7 ml/min at the end of treatment (P < 0.001). With ramipril, RPF response to L-NMMA increased from 60.1 +/- 12.2 to 87.8 +/- 9.2 ml/min (P = 0.018). The adjusted difference between treatments was -17.1 +/- 13.7 ml/min (P = 0.214). In accordance, telmisartan increased RPF at rest (i.e., without L-NMMA) from 652.0 +/- 27.0 to 696.1 +/- 31.0 ml/min (P = 0.047), whereas ramipril produced no significant changes in RPF. The more the basal NO activity improved, the greater was the vasodilatory effect on renal vasculature (r = 0.47, P < 0.001).


CONCLUSIONS
In patients with type 2 diabetes, telmisartan and ramipril both increased NO activity of the renal endothelium significantly, which in turn may support the preservation of cardiovascular and renal function.
Schmieder
Roland E
RE
Department of Nephrology and Hypertension, University of Erlangen-Nürnberg, Erlangen, Germany. roland.schmieder@rzmail.uni-erlangen.de
Delles
Christian
C
Mimran
Albert
A
Fauvel
Jean P
JP
Ruilope
Luis M
LM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001562:Benzimidazoles / Q000627:therapeutic use*; D001565:Benzoates / Q000627:therapeutic use*; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D003925:Diabetic Angiopathies / Q000188:drug therapy*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D017257:Ramipril / Q000627:therapeutic use*; D012079:Renal Circulation / Q000187:drug effects*; D000077333:Telmisartan
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D001562:Benzimidazoles; D001565:Benzoates; D009569:Nitric Oxide; D017257:Ramipril; D000077333:Telmisartan