ABSTRACT
BACKGROUND: Resistant hypertension is a specific condition that affects approximately 10% of subjects with hypertension, and is characterized by persistently high blood pressure levels even using therapy of three or more antihypertensive agents or with blood pressure control using therapy with four or more antihypertensive agents. Changes in lifestyle, such as physical exercise, are indicated for controlling blood pressure. However, investigating studies about this therapy in individuals with resistant hypertension are few. METHODS/DESIGN: This is a randomized controlled clinical trial. Forty-eight patients with resistant hypertension will be submitted to perform four short-term interventions: aerobic exercise sessions (mild-, moderate- and high-intensity) and control session, in random order and on separate days. After the short-term sessions, the patients will be randomly allocated into four groups for 8 weeks of follow-up: mild-, moderate- and high-intensity aerobic exercise, and a control group. The primary outcome is the occurrence of blood pressure reduction (office and ambulatory analysis, and acute and chronic effects). Secondary outcomes are autonomic and hemodynamic mechanisms: cardiac and vasomotor autonomic modulation, spontaneous baroreflex sensitivity, forearm blood flow and vascular resistance. DISCUSSION: The importance of exercise for hypertension has been known for decades, but little is known about the effects on patients with resistant hypertension. This study will help to understand whether different aerobic exercise intensities can induce different responses, as well as by what mechanisms adjustments in blood pressure levels may occur. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02670681 . Registered on 28 January 2016 (first version); Brazilian Registry Platform Clinical Trials: protocol RBR-5q24zh . Registered on 24 June 2015.
Subject(s)
Exercise Therapy/methods , Hypertension/therapy , Adult , Aged , Antihypertensive Agents/therapeutic use , Blood Pressure/drug effects , Brazil , Clinical Protocols , Drug Resistance , Female , Humans , Hypertension/diagnosis , Hypertension/physiopathology , Male , Middle Aged , Research Design , Single-Blind Method , Time Factors , Treatment OutcomeABSTRACT
This study aimed to analyze the vascular mechanisms involved in post-resistance decreases in blood pressure in patients with peripheral artery disease. 17 patients underwent 2 experimental sessions conducted in random order: resistance exercise (REx-3×10 reps in 8 exercises with intensity of ~ 60% of 1 RM) and control (C- resting on the exercise machines for 50 min). Before and after each experimental session, blood pressure, reflected wave indicators, pulse wave velocity, blood flow, blood flow post-reactive hyperemia and peripheral vascular resistance responses were obtained. Both sessions increased brachial systolic, diastolic and mean blood pressure (greatest increase REx: 11 mmHg; greatest increase C: 19 mmHg; P<0.01); however, the increases were greater after the C session (P<0.01). Reflected wave indicators increased only after the C session (P<0.06), while pulse wave velocity increased similarly after both sessions (P=0.66). Individual analyses indicated a large variability between patients in vascular variables responses. A single bout of REx decreased blood pressure in peripheral artery disease patients, and these responses were followed by changes in reflected wave indicators. The other factors presented high individual variability, and thus it was not possible to identify specific factors associated with blood pressure reduction in peripheral artery disease patients.
