Acute effects of intermittent hypoxia and acute aerobic exercise on Orexin-A level and blood pressure in pre-hypertensive patients

Background: This study was aimed to compare the effects of acute aerobic exercise and intermittent hypoxia on blood pressure and Orexin-A levels in patients with prehypertension. Methods: To this end, 10 male and female volunteers with prehypertension (51.7±3.1 years old) performed an aerobic exercise and an intermittent hypoxia session in separate days. The aerobic exercise consisted of 40 minutes of running on treadmill with intensity of 70% heart rate reserve. During intermittent hypoxia session, 5 minutes hypoxic air (11% oxygen) and 5 minutes normoxic air (room air) were inhaled intermittently at sitting position for an hour. Orexin-A levels, systolic and diastolic blood pressure were measured before and after interventions. Results: Systolic and diastolic blood pressure levels reduced significantly after aerobic exercise and intermittent hypoxia (P≤0.05). However Orexin-A levels decreased significantly only in intermittent hypoxic and this reduction was significantly correlated with the decrease in systolic blood pressure (P≤0.05). Conclusion: Performing an aerobic exercise with moderate intensity as well as an intermittent hypoxic session can have beneficial effects on blood pressure in patients with prehypertension and can be advised for them. In addition, intermittent hypoxia can reduce Orexin-A levels in these people. Therefore, it can be proposed for those who cannot participate in aerobic exercise program.