Obstructive sleep apnea is independently associated with arterial stiffness in ischemic stroke patients

Obstructive sleep apnea (OSA) is a predictor of all-cause mortality and recurrent vascular events following stroke. However, few studies have investigated the pathophysiology of OSA in ischemic stroke patients. Whether OSA independently increases arterial stiffness in ischemic stroke patients is determined by measuring the carotid-femoral pulse wave velocity (PWV) and via the central augmentation index (AIx). This cross-sectional study consecutively recruited 127 subacute ischemic stroke patients who were admitted to a teaching hospital for inpatient rehabilitation (median age, 61.3 years; IQR 53.6-72.7 years). Vascular measurements were performed following polysomnography. Multivariate linear regression analysis was performed to determine the relationship between arterial stiffness and OSA. Patients with severe OSA were significantly older, had significantly higher PWV and mean blood pressure, and a significantly higher risk of hypertension than those with non-severe OSA. The significant bivariate correlation between AIx@75 and the desaturation index (DI) (Spearman's ρ = 0.182, P = 0.040) became insignificant by multivariate regression analysis. The PWV was significantly correlated with the apnea-hypopnea index (AHI) (Pearson's r = 0.350, P = 0.000) and DI (Spearman's ρ = 0.347, P = 0.000). The correlation between PWV and OSA parameters, including presence of severe OSA, AHI and DI, remained significant by multivariate regression analysis with age, systolic blood pressure, diabetic mellitus, hypertension and the Barthel index as potential confounders. Arterial stiffness is independently associated with OSA, and PWV can be applied as an intermediate endpoint in further intervention trials of ischemic stroke patients with OSA.