Increases in different aspects of snoring, such as frequency and loudness, among patients with obstructive sleep apnea and established cardiovascular disease were associated with greater risks of cerebral but not cardiac events, according to study findings.
Increases in different aspects of snoring, such as frequency and loudness, among patients with obstructive sleep apnea (OSA) and established cardiovascular (CV) disease were associated with greater risks of cerebral but not cardiac events, according to study findings published in Chest.
Snoring is a common occurrence among patients with OSA, which may cause mechanical stress on the heart and vascular tree. “Snoring vibrations have been shown to induce carotid artery endothelial damage in experimental animal models, and self-reported or recorded snoring is associated with increased carotid artery intima-media thickness, carotid but not femoral artery atherosclerosis, unstable carotid plaques, and greater risks of stroke over cardiac events,” explained the study authors.
While concerning, the relationship of snoring among patients with OSA to risks of stroke and other major CV events remains unknown. Researchers sought to better understand this association by conducting post-hoc analyses of participants enrolled in the international Sleep Apnea cardioVascular Endpoints (SAVE) trial.
The study included 2687 participants of the SAVE trial with co-existing moderate-severe OSA and established coronary or cerebral CV disease, who were randomly administered either continuous positive airway pressure (CPAP) treatment with usual care or solely usual care. Participants self-reported snoring patterns (frequency and loudness) and breathing pauses via Berlin questionnaire at baseline and during a median follow-up of 3.5 years.
Cox proportional hazard models were utilized to evaluate adjudicated composites of primary CV outcomes, including CV death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for unstable angina, heart failure, or transient ischemic attack, as well as separately for cardiac and cerebral events.
Of the study cohort, 2540 patients (94.5%) had at least 2 measurements of frequency and loudness, and 2590 patients (96.5%) had at least 2 measurements of breathing pauses during follow-up for inclusion in the final imputation model
After completing follow-up analyses, increases of snoring frequency (adjusted hazard ratio [HR] = 1.10, 95% CI, 1.02—1.20; P = .015), loudness (HR = 1.16, 95% CI, 1.06—1.27; P = .001), and breathing pauses (HR = 1.16, 95% CI, 1.08—1.25; P < .001) were each associated with the primary composite CV outcome. All 3 snoring measures were found to be positively correlated with cerebral events, but not cardiac. Additionally, no significant interaction between CPAP treatment and snoring variables was observed for cerebral events.
Researchers highlight that study findings call for future studies to delineate the pathophysiology underlying snoring and stroke occurrence. “Trials investigating effective interventions for snoring in patients with OSA are warranted,” concluded the study authors.
Li J, McEvoy RD, Zheng D, et al. Self-reported snoring patterns predict stroke events in high-risk patients with obstructive sleep apnea: post-hoc analyses of the SAVE study. Chest. Published online July 14, 2020. doi:10.1016/j.chest.2020.05.615