Changes in sleep-disordered breathing severity and post-stroke outcomes in the first year after stroke.

Background: Sleep-disordered breathing (SDB) is common among stroke survivors and is associated with worse functional, cognitive, and neurologic outcomes after stroke. Little is known about the association between changes in SDB and changes in these outcomes over time.

Methods: Ischemic stroke (IS) patients identified through the Brain Attack Surveillance in Corpus Christi project were offered SDB testing with a portable respiratory monitor (ApneaLink Plus) shortly after stroke, and at 3-, 6-, and 12-months post-stroke. SDB was quantified using the respiratory event index (REI; apneas plus hypopneas per hour of recording). At 3-, 6-, and 12-months post-stroke, functional outcomes, cognitive outcomes, and neurologic outcomes were measured. Linear mixed models were fitted to obtain random slopes reflecting individual changes in REI and each of outcome over time, adjusted for multiple covariates. Associations between the resulting individual slopes for REI and each outcome were then evaluated using linear regression models.

Results: Of 482 IS patients with at least one REI measurement, in fully adjusted models, faster reduction in REI was not associated with faster improvement in functional (β = -0.06; 95 % CI: -0.15, 0.03, p = 0.16), cognitive (β = -0.03; 95 % CI: -0.12, 0.06, p = 0.51), or neurologic outcomes (β = -0.04; 95 % CI: -0.13, 0.05, p = 0.41).

Conclusions: In this observational study of stroke survivors, there was no clear association between the rate of improvement in SDB and improvement in functional, cognitive, or neurologic outcomes. It remains to be seen whether treatment of SDB might lead to improved outcomes among stroke survivors.