Aerobic Exercise in Postexercise Cardiovascular Responses in Resistant Hypertension: a Cross-over Trial

Study Overview
=================
Brief Summary
-----------------
Aerobic exercise has the potential to diminish blood pressure values. The aim of this study is to determine whether this potential is also applicable for those with resistant hypertension and whether exercise intensity plays a role in this context. We hypothesize that performing an aerobic exercise session reduces blood pressure values in resistant hypertensive patients in a dose-response relation with exercise intensity.

Detailed Description
-----------------
Exercise prescription is gathering great importance in preventive health. Several organizations endorse the performance of at least 150min/wk of moderate intensity or 75min/wk of higher intensities in order to achieve better health parameters in different contexts. Aerobic exercise is known to be an effective way to diminish BP levels post-session. These responses are widely applicable in hypertensive subjects, acting in aid of BP management treatment. Although these benefits of aerobic exercise are well known, few studies explore the potential of this intervention in resistant-to-treatment patients. Moreover, the effects different intensities of aerobic exercise in this population is scarce. Thus, the aim of this study is to determine the magnitude of BP responses, if there is any, of resistant hypertensive subjects to two different intensities of aerobic exercise, compared with a control session. For that, subjects will be enrolled for one pre-intervention cardiopulmonary exercise testing and three randomized intervention sessions: control, 50%HRmax and 75%HRmax. Prior and immediately after all intervention sessions (during 1h), forearm blood flow and reactive hyperemia will be assessed by venous occlusion plethysmography. After the sessions, 24h blood pressure will be assessed with an ambulatory blood pressure monitoring system.

Official Title
-----------------
Aerobic Exercise in Postexercise Cardiovascular Responses in Resistant Hypertension: a Cross-over Randomized Controlled Trial

Conditions
-----------------
Hypertension

Intervention / Treatment
-----------------
* Other: aerobic exercise


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: resistant-to-treatment hypertensive subjects (24h ambulatory BP above 130/80, or daytime ambulatory BP above 135/85, or night-time ambulatory BP above 120/70 in spite use of 3 anti-hypertensive medications of different classes, being one diuretic; or use of 4 or more anti-hypertensive medications). Exclusion Criteria: Muscle or skeletal abnormalities that preclude effort, abnormal exercise stress test, major illnesses that would preclude exercise effort or could influence in the outcome variables (pulmonary disease, valve disease, renal insufficiency, etc.)

Ages Eligible for Study
-----------------
Minimum Age: 25 Years
Maximum Age: 60 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control<br>sited rest for 45 minutes | |
| Experimental: higher intensity aerobic exercise<br>45 minutes of aerobic exercise at 75%HRmax | Other: aerobic exercise<br>* aerobic exercise (cycloergometer) at selected intensity (HRmax or equivalent)<br>|
| Experimental: lower intensity aerobic exercise<br>45 minutes of aerobic exercise at 50%HRmax | Other: aerobic exercise<br>* aerobic exercise (cycloergometer) at selected intensity (HRmax or equivalent)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ambulatory Blood Pressure Monitoring |  | 22h | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Forearm blood flow | Accessed by venous occlusion plethysmography. Compared with pre-intervention values | 1h | 
| Reactive hyperemia | Accessed by venous occlusion plethysmography. | pre and 30min post | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Resistant Hypertension, Aerobic Exercise