Abstract 9689: Endothelial Function & Sleep Quality

Abstract

Background: Sleep apnea is associated with cardiovascular disease (CVD). Although obstructive sleep apnea is also associated with abnormal endothelial function (EF), a precursor of CVD, it is unknown whether milder sleep disturbance affects EF. We investigated the relationship between sleep quality and EF, with the hypothesis that poor sleep quality, in the absence of sleep apnea, will be associated with endothelial dysfunction. Methods: 684 community participants free of CVD, 68% female, aged 37 to 60 years, were enrolled in the Emory-Georgia Tech Predictive Health Institute study. We measured CVD risk factors, sleep quality using the Epworth Sleepiness Scale (ESS) and selected questions from the Pittsburgh Sleep Quality Index (PSQI). EF was measured using brachial artery flow-mediated dilation (FMD). Multivariate analysis of covariance was used to adjust for age, race, gender, smoking, hypertension, diabetes, and body mass index. Results: Lower FMD measurements were correlated with higher ESS scores that reflect poor sleep quality (r = -0.0858, p = 0.03), a difference that remained significant after multivariate adjustment for the aforementioned risk factors (β = -0.0009, p = 0.03). Participants who reported cough or snoring during sleep in their PSQI questionnaire also tended to have lower FMD (6.2±3.4% compared to 6.9±4.3%, p = 0.056), a difference that remained significant after multivariate adjustment for risk factors above (p = 0.03). Conclusion: In a community-based population without clinically diagnosed sleep apnea, we demonstrate a significant association between sleep quality assessed by questionnaires and EF. Poor sleep quality reflected by symptoms of cough / snoring, or a high ESS score, may contribute to CVD and hypertension by adversely affecting EF.