Influence of high risk of obstructive sleep apnea on adherence to antihypertensive treatment in outpatients.

Obstructive sleep apnea (OSA) is a common cause of high blood pressure (BP). Many patients, however, have uncontrolled BP because of nonadherence to antihypertensive medication. The possibility that OSA influences adherence has not been investigated to date. The authors sought to explore the possible association between high risk of OSA and nonadherence. This study was carried out in a hypertension outpatient clinic. Adherence to medication, high risk of OSA, and sleepiness were evaluated in a cross-sectional study. These variables were identified using the eight-item Morisky, STOP-Bang, and Epworth scales, respectively. A total of 416 patients with hypertension were enrolled (32% male, aged 65±11 years). Nonadherence was identified in 71 (17%) individuals. The prevalence of high risk of OSA was 323 (78%) and of somnolence was 136 (33%). High risk of OSA was associated with nonadherence, showing a prevalence ratio (PR) of 2.6 (95% confidence interval [CI], 1.3-5.6) and retained significance after adjustment for sleepiness (PR, 2.3; 95% CI, 1.1-4.9 [P=.011]). Sleepiness was also associated with nonadherence (PR, 1.7; 95% CI, 1.1-2.6 [P=.003]). High risk of OSA and sleepiness are associated with nonadherence. These conditions, if treated, may allow for achieving better outcomes and improvement of adherence to medication.