Abstract 17258: Effects of Aerobic Exercise Intensity on Ambulatory Blood Pressure Monitoring and Vascular Responses in Resistant Hypertension: A Cross-over Trial

Abstract

Introduction: Patients with resistant hypertension are usually exposed to poor blood pressure (BP) control, resulting in clinical vulnerability, possibility of device-based procedures (denervation), and cumulative costs with drug therapy. Regular aerobic exercise promotes marked benefits in hypertension, including the subset of resistant patients. However, little is known about acute effects of exercise on patients with resistant hypertension. Hypothesis: We hypothesized that a single aerobic session would reduce BP and improve vascular variables. Thus, we compared ambulatory BP and vascular parameters in response to two intensities of aerobic sessions and a non-exercise control session in patients with resistant hypertension. Methods: After a maximal exercise test, 18 patients (54±6 years, 30.2±4.9 kg/m2) participated in three interventions in random order, crossover design, and on separate days: control session (45’ of rest), light intensity (LI) and moderate intensity (MI) sessions (45’ of aerobic exercise at 50% and 75% of HRmax, respectively). Ambulatory BP monitoring (Space Labs, 90702) comprised a 19h period after each session. Vascular variables were measured at the non-dominant forearm by venous occlusion plethysmography (Hokanson Inc) before and up to 1h after all sessions. Results: Compared with control session, both exercise sessions reduced ambulatory systolic BP in a 5h period (LI: -7.7±2.4mm Hg and MI: -9.4±2.8mm Hg, p<0.01), whereas only LI session reduced diastolic BP (-5.7±2.2mm Hg, p<0.01). In addition, LI induced lower values in systolic and diastolic BP during 10h-daytime (-3.8±1.3mm Hg and -4.0±1.3mm Hg, respectively, p<0.02), nighttime (-6.0±2.4 mm Hg and -6.1±1.6mm Hg, respectively, p<0.05) and in diastolic BP during 19h (-4.8±1.2mm Hg, p<0.01). Forearm blood flow decreased only at minute 50 after LI (p<0.05), with no other changes. In control and LI sessions, forearm vascular resistance increased at the end of 1h recovery period and in MI session, it decreased immediately after the intervention (p<0.05). Conclusions: A single aerobic exercise session in light or moderate intensities induces beneficial changes in ambulatory BP in resistant hypertension, with advantages in effect length for lighter intensities.