Pharmacodynamic Influences of Candesartan, Atenolol, Hydrochlorothiazide and Drug Combinations in Hypertensive Patients

Angiotensin receptor antagonists (ARA), beta-blockers and diuretics do not seem to confer equivalent cardiovascular protection in hard outcomes clinical trials (beta blockers inferior). These results may be explained by differences in their effects on sympathetic activity, oxidative stress, inflammation and renin angiotensin system activation. How diuretic addition to first line therapy with ARAs and beta-blockers modulates neurohumoral and hemodynamic parameters is not well understood. The main hypothesis of this study is that an ARA (candesartan) combined or not with a diuretic will not increase sympathetic activity as much as a beta blocker (atenolol). Secondary hypothesis are of similar nature but relate to hemodynamic parameters, oxidative stress markers, inflammatory markers, or the renin angiotensin system. The main objective of this study is to assess and compare the effects of candesartan and atenolol and their combination with low dose diuretic therapy on the autonomic nervous system, hemodynamic parameters,on oxidative stress, on inflammatory markers, and on the renin-angiotensin system. Protocol sponsored by Astra Zeneca canada