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Treatment with irbesartan or atenolol improves endothelial function in essential hypertension
B von zur Mühlen1, T Kahan, A Hägg
1Department of Internal Medicine, University Hospital, Uppsala, Sweden. bengt.muhlen@medsci.uu.se
Insights
Antihypertensive treatments with irbesartan or atenolol significantly improved endothelium-dependent vasodilation in hypertensive patients. Both drugs demonstrated comparable efficacy in enhancing blood vessel function.
Area of Science:
- Cardiovascular Medicine
- Pharmacology
Background:
- Essential hypertension is characterized by impaired endothelium-dependent vasodilation.
- The role of specific antihypertensive agents in improving endothelial function requires further investigation.
Purpose of the Study:
- To compare the effects of irbesartan (angiotensin II subtype-1 receptor antagonist) and atenolol (beta1-receptor antagonist) on endothelium-dependent vasodilation in hypertensive patients.
- To determine if antihypertensive treatment can restore normal endothelial function.
Main Methods:
- A double-blind, randomized study involving 34 patients with mild-to-moderate essential hypertension.
- Patients received either irbesartan or atenolol for 3 months after a placebo run-in period.
- Forearm blood flow was measured using venous occlusion plethysmography during methacholine and sodium nitroprusside infusions to assess endothelium-dependent and independent vasodilation, respectively.
Main Results:
- Both irbesartan and atenolol effectively lowered blood pressure similarly.
- A significant improvement in endothelium-dependent vasodilation was observed with both drugs, with no significant difference between them.
- No significant changes in endothelium-independent vasodilation were noted with either treatment.
Conclusions:
- Three months of antihypertensive therapy with either irbesartan or atenolol improves endothelium-dependent vasodilation in hypertensive patients.
- These findings suggest that targeting the renin-angiotensin system or beta-adrenergic receptors can positively impact endothelial function.
Objectives:
To investigate if antihypertensive treatment could improve endothelium-dependent vasodilatation in hypertensive patients, and whether the angiotensin II subtype-1 (AT1)-receptor antagonist irbesartan and the beta1-receptor antagonist atenolol would differ in this respect.
Subjects And Methods:
Thirty-four patients (28 men and six women) with mild-to-moderate essential hypertension (diastolic blood pressure 90-120 mmHg) were randomized to once daily 150-300 mg irbesartan or 50-100 mg atenolol in a double-blind fashion, preceded by a placebo run-in period. Forearm blood flow (FBF) was assessed by venous occlusion plethysmography during local intra-arterial infusions of methacholine and sodium nitroprusside, to evaluate endothelium-dependent and endothelium-independent vasodilatation, respectively. Measurements of FBF were undertaken at the end of the run-in placebo period and repeated after 3 months of active antihypertensive treatment.
Results:
Irbesartan and atenolol induced a similar decline in blood pressure (from 171/107 to 158/98 mmHg, P < 0.05), and improved endothelium-dependent vasodilatation (e.g. an increase in FBF response to 4 microg/min methacholine from 325 +/- 29% to 411 +/- 41%, P < 0.05), with no difference between the two study drugs. No significant changes in endothelium-independent vasodilatation were induced by irbesartan or by atenolol.
Conclusions:
The present study shows that 3 months of antihypertensive therapy with irbesartan or atenolol improves endothelium-dependent vasodilatation.