Sildenafil and Exercise Capacity in Hypertension

Study Overview
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Brief Summary
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Hypertension (persistently elevated blood pressure) is a major risk factor for heart disease and stroke. Hypertensive individuals show a reduced exercise capacity, which is present from a very early stage and contributes to their increased cardiovascular risk. Sildenafil belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors, and it works by enhancing the effects of nitric oxide, a substance that dilates blood vessels and increases blood flow. We hypothesize that sildenafil, because of its effect on nitric oxide and blood flow, will improve exercise capacity in hypertensive patients. Therefore, the main aim of the study is to investigate the effects of PDE5 inhibition on exercise capacity and vascular function in hypertension, and to compare these effects in hypertensive patients and healthy controls.

Official Title
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Effects of the Selective Phosphodiesterase Type 5 Inhibitor Sildenafil Citrate on Exercise Capacity and Vascular Function in Hypertensive Subjects

Conditions
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Hypertension

Intervention / Treatment
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* Drug: sildenafil
* Drug: hydralazine
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male (age range: 18 - 70 years) Appropriate blood pressure range Hypertensive - Systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg Controls - Systolic BP <140 mmHg and diastolic BP <90mmHg Written informed consent Exclusion Criteria: Female History of coronary artery, cerebrovascular or peripheral vascular disease within the last 6 months Total cholesterol >6.5 mmol/L Current alcohol abuse Diabetes mellitus Asthma Taking any anti-hypertensive, vasoactive or endothelial function modifying drugs which cannot be withdrawn for the purpose of the study ECG evidence of clinically significant arrhythmia or cardiac ischaemia Clinically significant abnormality on screening blood test Contraindication to strenuous exercise Current involvement in other research projects Other clinically relevant conditions Lack of written informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br> | Drug: sildenafil<br>* 50mg 3 times daily for 7 days<br>* Other names: Viagra;Drug: hydralazine<br>* 25mg 3 times daily for 7 days<br>Drug: placebo<br>* 3 times daily for 7 days<br>|
| Active Comparator: 2<br> | Drug: sildenafil<br>* 50mg 3 times daily for 7 days<br>* Other names: Viagra;Drug: hydralazine<br>* 25mg 3 times daily for 7 days<br>Drug: placebo<br>* 3 times daily for 7 days<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak oxygen uptake (VO2) during exercise |  | 1 week of treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exercise systolic blood pressure |  | Maximal exercise | 
| Pulse wave velocity and pulse wave analysis |  | Before and after maximal exercise | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypertension, Exercise capacity, PDE5 inhibitors