Snoring is associated with increased risk of cerebral events in patients with obstructive sleep apnea (OSA) and established cardiovascular disease (CVD), according to study results published in Chest.
Study researchers sought to determine the associations of snoring patterns and major cardiovascular (CV) events relative to OSA. The study was a collection of post-hoc analyses of de-identified participant data from the Sleep Apnea cardioVascular Endpoints (SAVE) study (ClinicalTrials.gov Identifier: NCT00738179). In total, the primary analysis included 2687 participants with co-existing moderate-to-severe OSA and established coronary or cerebrovascular CVD. All patients were randomly assigned to treatment with either continuous positive airway pressure (CPAP) plus usual care or usual care alone. Patient follow-up occurred at a median of 3.5 years.
The investigators used adjusted Cox proportional hazards models to examine associations between self-reported snoring patterns, such as frequency, loudness, breathing pauses, and adjudicated composites of CV outcomes. CV outcomes included CV death, non-fatal myocardial infarction, nonfatal stroke, and hospitalization for unstable angina, heart failure, or transient ischemic attack. The models were also used to examine the association between snoring patterns with cardiac and cerebral events. Snoring and breathing characteristics were collected from responses to the Berlin questionnaire, which were administered at baseline and 6, 24, and 48 months, as well as at the end of the study.
An increase in all 3 self-reported snoring characteristics at any time during follow up was associated with the primary composite outcome: 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). In a fully adjusted model, snoring loudness was significantly associated with cerebral events (HR, 1.33; 95% CI, 1.14-1.55; P <.001) and stroke (HR, 1.29; 95% CI, 1.09-1.52; P =.002). There was no significant interaction between CPAP treatment and snoring variables in terms of cerebral events.
Limitations of the study included the potential for residual confounding and the lack of adjustment for other potential confounders, such snoring history, CVD severity, level of self-care, and patient health literacy, which may have affected findings.
While the clinical implications of the findings were not made clear, the researchers of this study suggest the results “call for future studies to elucidate the pathophysiology underlying snoring and stroke occurrence, and trials investigating effective interventions for snoring in patients with OSA are warranted.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
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