Wake-up stroke is not associated with obstructive sleep apnea.

OBJECTIVE/

BACKGROUND

Obstructive sleep apnea is a risk factor for stroke. This study sought to assess the relationship between obstructive sleep apnea (OSA) and wake-up strokes (WUS), that is, stroke symptoms that are first noted upon awakening from sleep.

PATIENTS/

METHODS

In this analysis, 837 Brain Attack Surveillance in Corpus Christi (BASIC) project participants completed an interview to ascertain stroke onset during sleep (WUS) versus wakefulness (non-wake-up stroke, non-WUS). A subset of 316 participants underwent a home sleep apnea test (HSAT) shortly after ischemic stroke to assess for OSA. Regression models were used to test the association between OSA and WUS, stratified by sex.

RESULTS

Of 837 participants who completed the interview, 251 (30%) reported WUS. Among participants who underwent an HSAT, there was no significant difference in OSA severity [respiratory event index (REI)] among participants with WUS [median REI 17, interquartile range (IQR) 10, 29] versus non-WUS (median REI 18, IQR 9, 30; p = 0.73). OSA severity was not associated with increased odds of WUS among men [unadjusted odds ratio (OR) 1.011, 95% confidence interval (95% CI) 0.995, 1.027] or women (unadjusted OR 0.987, 95% CI 0.959, 1.015). These results remained unchanged after adjustment for age, congestive heart failure, body mass index, and pre-stroke depression in men (adjusted OR 1.011, 95% CI 0.994, 1.028) and women (adjusted OR 0.988, 95% CI 0.959, 1.018).

CONCLUSIONS

Although OSA is a risk factor for stroke, the onset of stroke during sleep is not associated with OSA in this large, population-based stroke cohort.