Self-reported obstructive sleep apnea, simple snoring, and various markers of sleep-disordered breathing as predictors of cardiovascular risk.

PURPOSE: Our objective was to investigate whether self-reported obstructive sleep apnea (OSA), simple snoring, and various markers of sleep-disordered breathing (SDB) are associated with cardiovascular risk.

METHODS: We examined a representative nationwide cohort of 5177 Finnish adults aged ≥30 years. The participants underwent measurement of traditional cardiovascular risk factors and answered SDB-related questions derived from the Basic Nordic Sleep Questionnaire, which were used to operationalize self-reported OSA. The primary end point was incidence of a cardiovascular event (cardiovascular mortality, non-fatal myocardial infarction, non-fatal stroke, hospitalization for heart failure, or coronary interventions).

RESULTS: During a median follow-up of 11.2 years and 52,910 person-years of follow-up, 634 participants suffered a cardiovascular event. In multivariable-adjusted Cox models, self-reported OSA (hazard ratio [HR] 1.34; 95 % confidence interval [CI] 1.04-1.73; p = 0.03) was an independent predictor of cardiovascular events. Self-reported simple snoring by itself was not associated with future cardiovascular events (HR 0.88 versus non-snorers, 95 % CI 0.75-1.04, p = 0.15). However, among snorers (n = 3152), frequent breathing cessations (HR 2.19, 95 % CI 1.26-3.81, p = 0.006) and very loud and irregular snoring (HR 1.82, 95 % CI 1.31-2.54, p < 0.001) were associated with cardiovascular risk.

CONCLUSIONS: Self-reported OSA and SDB-related snoring variables are associated with cardiovascular risk, whereas simple snoring is not. In clinical practice and in surveys, questions concerning only habitual snoring should be amended with questions focusing on respiratory pauses and snoring stertorousness, which can be used to estimate the risk of OSA and cardiovascular events.