Effect of CPAP therapy on daytime cardiovascular regulations in patients with obstructive sleep apnea

Abstract Obstructive sleep apnea (OSA) is a sleep disorder with a high prevalence that causes pathological changes in cardiovascular regulation during the night and also during daytime. We investigated whether the treatment of OSA at night by means of continuous positive airway pressure (CPAP) improves the daytime consequences. Twenty-eight patients with OSA, 18 with arterial hypertension, 10 with normal blood pressure, were investigated at baseline and with three months of CPAP treatment. Ten age and sex matched healthy control subjects were investigated for comparisons. We recorded a resting period with 20 min quiet breathing and an exercise stress test during daytime with ECG and blood pressure (Portapres). The bicycle ergometry showed a significant reduction of the diastolic blood pressure at a work load of 50 W and 100 W ( p