Effects of aerobic exercise intensity on ambulatory blood pressure and vascular responses in resistant hypertension: a crossover trial

Background: Resistant hypertension often exposes patients to poor blood pressure ( BP) control, resulting in clinical vulnerability, possible need for device-based procedures ( denervation) and increased therapy costs. Regular exercise markedly benefits patients with hypertension, including resistant patients. However, little is known about short-term exercise effects in resistant hypertension. Objective: To evaluate acute hemodynamic effects of exercise in resistant hypertension. Method: After maximal exercise testing, 20 patients ( 54.0 +/- 5.7 years, 30.2 +/- 4.9 kg/m(2)) with resistant hypertension participated in three crossover interventions, in random order, and on separate days: control ( 450 of rest), and light intensity and moderate intensity ( 450 of aerobic exercise at 50 and 75% of maximum heart rate, respectively). Ambulatory BP, forearm blood flow ( with subsequent calculation of vascular resistance), and reactive hyperemia were measured before and after interventions trough venous occlusion plethysmography. Results: Compared with control, both exercise intensities reduced ambulatory systolic pressure over 5 h ( light: -7.7 +/- 2.4mmHg and moderate: -9.4 +/- 2.8 mmHg, P< 0.01), whereas only light intensity reduced diastolic pressure ( -5.7 +/- 2.2mmHg, P< 0.01). Light intensity also lowered systolic and diastolic pressures over 10-h daytime ( -3.8 +/- 1.3 and -4.0 +/- 1.3mmHg, respectively, P< 0.02), night-time ( -6.0 +/- 2.4 and -6.1 +/- 1.6 mmHg, respectively, P< 0.05), and diastolic pressure over 19 h ( -4.8 +/- 1.2 mmHg, P< 0.01). Forearm blood flow changed ( decreased) compared with baseline only at 50 min after light intensity ( P< 0.05). After the control and light intensity sessions, vascular resistance increased at the end of 1 h, and after moderate intensity, it decreased only at the moment ( similar to 2 min) immediately after intervention ( P< 0.05). Conclusion: A single session of light or moderate aerobic exercise acutely reduces ambulatory BP in resistant hypertension, although benefits persist longer following light intensity.