Hypertension
Conditions
Keywords
Hypertension, Exercise capacity, PDE5 inhibitors
Brief summary
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.
Interventions
DRUGsildenafil
50mg 3 times daily for 7 days
DRUGhydralazine
25mg 3 times daily for 7 days
DRUGplacebo
3 times daily for 7 days
Sponsors
University of Edinburgh
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
18 Years to 70 Years
Healthy volunteers
Yes
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mellitus * Asthma * Taking any anti-hypertensive, vasoactive or endothelial function modifying drugs which cannot be withdrawn for the purpose of the study * ECG evidence of clinically significant arrhythmia or cardiac ischaemia * Clinically significant abnormality on screening blood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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Peak oxygen uptake (VO2) during exercise | 1 week of treatment |
Secondary
| Measure | Time frame |
|---|---|
| Exercise systolic blood pressure | Maximal exercise |
| Pulse wave velocity and pulse wave analysis | Before and after maximal exercise |
Countries
United Kingdom
Outcome results
None listed