MINNEAPOLIS – Continuous positive airway pressure works similarly well at lowering blood pressure in real-world clinical practice as in clinical trials, according to a cohort study of 880 patients with sleep-disordered breathing and hypertension.
The patients, 598 with hypertension that responded to therapy and 282 with idiopathic resistant hypertension, were all treated at a tertiary-care sleep disorders center between 2010 and 2013.
Dr. Harneet Walia
On average, a year after starting continuous positive airway pressure (CPAP), they had a reduction of 3.0 mm Hg in systolic blood pressure, 2.2 mm Hg in diastolic blood pressure, and 2.5 mm Hg in mean arterial pressure in analyses adjusted for potential confounders, researchers reported at the annual meeting of the Associated Professional Sleep Societies.
The benefit was similar regardless of whether hypertension was resistant or not, although patients with the resistant form had higher blood pressure – especially systolic blood pressure – at this time point.
"Our real-world experience is consistent with the blood pressure reduction seen with the use of CPAP in the rigorous clinical trials," commented lead researcher Dr. Harneet K. Walia, assistant professor of family medicine with the sleep disorders center at the Cleveland Clinic. "The clinic-based effectiveness data of CPAP on blood pressure in this pragmatic clinical study were similar in the resistant hypertension and non–resistant hypertension groups."
Study findings were essentially the same when neck size was substituted for body mass index as a potential confounder (although the multivariate model had a better fit) and when analyses were restricted to the 82% of patients who were adherent to CPAP, according to self-report.
In an interview, session cochair Dr. Cathy Anne Goldstein, assistant professor of neurology at the University of Michigan, Ann Arbor, said, "This is a promising study that does show the association of treating obstructive sleep apnea with CPAP and reducing blood pressure. This was nice because it showed it wasn’t just the patients who were refractory – it was all comers with hypertension who had a benefit."
"This isn’t new, but it’s confirmatory of what some other studies have shown," she added. "The more information we can get, the better, because there have been some conflicting results."