Arterial Function After Two Different Physical Exercise Intensities in Prehypertension

Study Overview
=================
Brief Summary
-----------------
Individuals with prehypertension, diagnosed according to the 7th Brazilian Guidelines on Hypertension with the presence of systolic blood pressure (SBP) between 121 and 139 and / or diastolic (DBP) between 81 and 89 mmHg, are more likely to become hypertensive and to develop cardiovascular complications. Moreover, they already have alterations in the function of large arteries that may play a role in the development of the disease in the future. An option in the prevention / treatment of hypertension is the moderate intensity physical training, but high intensity interval training offers the possibility of greater exercise adherence, since it can be performed with less volume and less time spent, with the same benefits than moderate exercise, or even higher, being preferred by the population. Among these benefits, the investigators can mention the post-exercise hypotension (PEH) which occurs in normotensive, prehypertensive, and hypertensive individuals, due the decreased in sympathetic nerve activity and improved in vascular function. Also, selected participants with prehypertension can present a profile of masked hypertension, identified only by 24 hours ambulatory BP monitoring (ABPM). Given the possible differences between vascular responses to exercise intensities, the investigators intend to compare, in prehypertensive patients, the vascular responses of large arteries by noninvasive methods and PEH to a session of high intensity exercise and a session of moderate intensity continuous exercise. In addition, to study some of the possible physiological variables involved in this response by measuring heart rate variability. It is expected to find differences in vascular responses according to the presence of masked hypertension. Twenty two prehypertensive individuals aged between 30 and 60 years of both sexes will be studied. Subjects will perform cardiopulmonary testing and baseline vascular measurements (central pressure and pulse wave velocity measurements by three different methods), as well as 24 -hour ABPM. The vascular measurements will be repeated immediately after, and 24 hours after each session. Each participant will perform the session of one type of exercise in one day, and after three days will perform the other, with random distribution to the sequence of exercise type. Participants will perform 24-hour ABPM prior to exercise and for 24 hours after each exercise session. Data will be compared by appropriate statistical analysis.

Detailed Description
-----------------
The measurement of central pressure and pulse wave velocity are achieved by three follow devices: Complior® , Sphygmocor® and Arteriograph®. The heart rate variability is achieved by Polar® device.

Official Title
-----------------
Evaluation of Vascular Responses to Moderate-intensity Continuous and High-intensity Interval Physical Exercise in Individuals With Prehypertension: a Randomized Trial

Conditions
-----------------
Prehypertension, Masked Hypertension

Intervention / Treatment
-----------------
* Behavioral: Moderate intensity continuous training - session
* Behavioral: High intensity interval training - session


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age ≥30 and ≤60 years old Prehypertension, according to the 7 th Brazilian Arterial Hypertension Guideline values Both sexes Those who agree to sign the free and informed consent form Exclusion Criteria: Engaged in other studies or programs of physical activity or training In drug treatment (for hypertension or other metabolic disease) Smokers Unable to perform exercise on exercise bike Presence of cardiovascular or metabolic disease (eg diabetes, hypercholesterolemia) Pregnant

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 60 Years

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

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

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

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Moderate intensity continuous training - session<br>The volunteers perform a 30-minute moderate-intensity exercise session on the exercise bike. | Behavioral: Moderate intensity continuous training - session<br>* Moderate exercise continuous exercise 30 minuts session<br>Behavioral: High intensity interval training - session<br>* The high intensity interval exercise sessions are isocaloric to the moderate intensity continuous exercise, therefore, the necessary exercise time equivalent to 30 minutes of the moderate exercise continuous exercise session was calculated.<br>|
| Active Comparator: High intensity interval training - session<br>The volunteers perform a session of high intensity interval exercise on the exercise bike. | Behavioral: Moderate intensity continuous training - session<br>* Moderate exercise continuous exercise 30 minuts session<br>Behavioral: High intensity interval training - session<br>* The high intensity interval exercise sessions are isocaloric to the moderate intensity continuous exercise, therefore, the necessary exercise time equivalent to 30 minutes of the moderate exercise continuous exercise session was calculated.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in arterial stiffness by piezoelectric method (Complior) | Changes in arterial function behavior in response to two different physical exercise intensities. | Baseline, immediately after exercise and 24 hours after exercise | 
| Methods of measuring arterial stiffness: piezoelectric, tonometric and oscillometric | Comparison of methods of evaluation of early markers of cardiovascular disease. | Baseline. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in heart rate variability | Changes in heart rate variability | Baseline, immediately after exercise and 24 hours after exercise | 
| Ambulatory systolic blood pressure measurement | Ambulatory measurement of 24-hours ambulatory systolic blood pressure | During 24 hours after each exercise session | 
| Ambulatory diastolic blood pressure measurement | Ambulatory measurement of 24-hours ambulatory diastolic blood pressure | During 24 hours after each exercise session | 
| Changes in arterial stiffness by three methods: piezoelectric, tonometric and oscillometric | Changes in arterial function behavior in response to two different physical exercise intensities by three methods. | Baseline, immediately after exercise and 24 hours after exercise. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Arterial function, Physical exercise, Arterial stiffness, Ambulatory Measurement of Blood Pressure