Effects of continuous positive airway pressure on blood pressure in hypertensive patients with obstructive sleep apnea: a 3-year follow-up.

Objective: Several studies have reported a small yet significant decrease in blood pressure (BP) with continuous positive airway pressure (CPAP) application in patients with obstructive sleep apnea (OSA). We investigated the long-term efficiency of CPAP in the management of hypertensive patients with OSA on top of conventional antihypertensive medication.
Methods: We followed 91 nonsleepy patients (aged 54 ± 9 years, 69 men) with essential hypertension and newly diagnosed moderate-to-severe OSA (apnea-hypopnea index, 38 ± 24 events/h on polysomnography) for a mean period of 3.1 years, after switching them to antihypertensive treatment targeting office BP less than 140/90 mmHg (<130/80 mmHg in diabetic patients). Participants were defined as on-CPAP if they adhered to CPAP treatment during the whole follow-up period (N = 41), whereas those that did not follow CPAP therapy served as controls (N = 50).
Results: By the end of follow-up, on-CPAP patients and controls exhibited similar SBP and DBP levels (133 ± 12 versus 133 ± 13 mmHg, 84 ± 9 versus 85 ± 9 mmHg, respectively, P > 0.05 for all), number of patients with controlled hypertension (71 versus 70%, P > 0.05), and number of antihypertensive drugs needed to achieve BP control (2.28 ± 1.09 versus 2.11 ± 0.72, P > 0.05). In a subgroup of patients (N = 34) in whom ambulatory BP monitoring was also performed, 24-h BP levels did not differ between the two groups (125 ± 10/76 ± 7 mmHg versus 123 ± 11/75 ± 10 mmHg, P > 0.05). In multiple regression models, CPAP application was not associated with changes in BP levels.
Conclusion: In nonsleepy, hypertensive, OSA patients on conventional antihypertensive treatment, long-term CPAP application is not associated with lower BP levels or a need for less antihypertensive drugs for BP control.