Endothelial dysfunction and arterial stiffness in ischemic stroke: the role of sleep-disordered breathing.

BACKGROUND AND
PURPOSE: Sleep-disordered breathing (SDB) represents a risk factor for cardiovascular morbidity after a cerebral ischemic event (acute ischemic event, ischemic stroke, or transient ischemic attack). In the present study, endothelial function and arterial stiffness were analyzed in patients who experienced a postacute ischemic event with relation to SDB, sleep disruption, and nocturnal oxygenation parameters.
METHODS: SDB was assessed by full polysomnography in patients with acute ischemic event 3 months after the admission at our stroke unit. Moderate-severe SDB was defined according to the apnea-hypopnea index as apnea-hypopnea index ≥ 20. Endothelial function and arterial stiffness were assessed by peripheral arterial tonometry using Endo-PAT 2000.
RESULTS: Thirty-seven patients were included. The augmentation index was significantly different between patients with apnea-hypopnea index <20 and apnea-hypopnea index ≥ 20 (22.4 ± 15.6% versus 34.6 ± 21.6%; P=0.042), whereas reactive hyperemia index level was not (2.02 ± 0.65 versus 2.31 ± 0.61; P=0.127). Patients with apnea-hypopnea index ≥ 20 showed an increased risk for arterial stiffness (odds ratio, 5.98 [95% CI, 1.11-41.72]) even when controlling for age, sex, body mass index, hypertension, and diabetes mellitus. The augmentation index was correlated with the arousal index (P=0.010) and with mean O2 saturation (P = 0.043).
CONCLUSIONS: Poststroke patients with moderate-severe SDB were more prone to have increased arterial stiffness, although we did not find significant differences in endothelial function. Arterial stiffness also correlated with sleep disruption (arousal index) and mean O2 saturation.