Regular snoring is associated with uncontrolled hypertension: A longitudinal objective assessment of nightly snoring and blood pressure

Abstract

BackgroundSnoring may be a risk factor for cardiovascular disease and stroke. However, most prior studies have relied on subjective snoring evaluation from self-reports, or relatively short time-scale objective measures in small samples. This study assessed the prevalence of objectively quantified snoring measured over multiple months, and its association with blood pressure and hypertension.Methods12,287 participants were monitored nightly in-home for approximately six months using an under-the-mattress sleep sensor to estimate the average percentage of sleep time spent snoring per night and the apnea-hypopnea index (AHI). Blood pressure cuff measurements from multiple daytime assessments were averaged to define uncontrolled hypertension based on mean systolic blood pressure ≥140 mmHg and/or a mean diastolic blood pressure ≥90 mmHg. Associations between snoring and uncontrolled hypertension were examined using logistic regressions controlled for age, body mass index (BMI), sex, and AHI.FindingsParticipants were predominantly middle-aged (mean±SD; 50±12 y) and male (88%). There were 2,467 cases (20%) with uncontrolled hypertension. Approximately 29, 14 and 7% of the study population snored for an average of >10, 20, and 30% per night, respectively. A higher proportion of time spent snoring (75th vs. 5th; 12% vs. 0·04%) was associated with an ∼1·9-fold increase (OR [95%CI]; 1·87 [1·63, 2·15]) in uncontrolled hypertension independent of sleep apnea. The effect size of the association between snoring and uncontrolled hypertension was higher in younger adults and those who were not obese (BMI <30 kg/m2).InterpretationsMulti-night recordings in a large consumer sample indicate that snoring is common, and that snoring duration is positively associated with hypertension. These findings highlight the potential clinical utility of simple, objective, and non-invasive methods to detect snoring.Funding SourceThis was an unfunded, investigator-initiated study led by the Adelaide Institute for Sleep Health sleep research team. DJE is supported by a National Health and Medical Research Council (NHMRC) of Australia Leadership Fellowship (1196261).Research in contextEvidence before this studyWe searched PubMed, Google, and Google Scholar for research articles published in English up to June 1, 2022, using common search terms including “wearable”, “nearable”, “sleep apnea”, and “snoring”. Articles were also retrieved through searching the citations of known literature.Snoring is a major feature of sleep disordered breathing, including hypopnea events which reflect partial airway obstruction typically with snoring. A meta-regression of 63 studies reported a highly variable snoring prevalence of between 2-83% in men and between 1-71% in women.These studies relied on self-reported snoring assessments, which may not be sufficiently reliable to evaluate prevalence and potential snoring impacts on cardiovascular health outcomes. A few small scale clinical and epidemiological studies with objective snoring assessments on a single night suggest associations between snoring and adverse cardiovascular health outcomes.However, a recent meta-analysis indicates that assessment of sleep apnea severity is highly variable night to night. Like sleep apnea severity, single time-point estimation of snoring parameters may not reliably reflect potentially problematic features of snoring and cumulative exposure risks over time.Added value of this studyWe investigated the prevalence of snoring and its association with uncontrolled hypertension on the largest dataset to date (>12,000 participants), including multi-night assessment of snoring over ∼6 months (∼2 million nights in total). Approximately 15% of the study population snored for an average of 20% per night, and a higher proportion of time spent snoring was associated with an 87% increase in uncontrolled hypertension independent of sleep apnea severity.Implications of all the available evidenceThese findings provide important insight into the consequences of snoring on hypertension risk and highlight the potential need to consider snoring as part of clinical care and management of sleep problems. These findings demonstrate the potential clinical utility of simple, objective, and non-invasive methods to detect and evaluate snoring.