Disclosures None Snoring and Its Outcomes Jolie Chang, MD Otolaryngology, Head and Neck Surgery University of California, San Francisco February 14, 2014 Otolaryngology Head Outline Snoring and OSA Acoustics of snoring and sound analysis Clinical effects of primary snoring Pathophysiology Relationship to cardiovascular disease and mortality Snoring and OSA Chronic habitual snoring OSA 20% women; 40% men Most common symptom of OSA (occurring in 70-95%) AHI >5 + excessive daytime sleepiness Primary snoring AHI <5; no daytime symptoms Snoring risk factors Age, sex, obesity, ETOH or sedative use, smoking, nasal obstruction, asthma, COPD. 1
Snoring - Acoustics Snoring is a poor predictor of OSA Snoring = noise generated when air flows though a narrowed upper airway Sound source: oscillation of soft palate >> pharyngeal walls, epiglottis, tongue Atonia of upper airway -> narrowing/increased resistance-> turbulent airflow-> vibration of pharyngeal tissues Wisconsin Sleep Cohort Study 602 subjects: PSG and self reported snoring Pevernagie et al. Sleep Med Rev. 2010. Young et al. NEMJ. 1993. Snoring Intensity and OSA Snoring sounds differ in OSA 1600 Habitual snorers PSG and objective measures Significant correlation between loudness of snoring and AHI AHI < 5 46dB AHI >50 60dB Snore sound analysis goals: Predict pts with OSA sensitivity 86-100%; specificity 50-80% (Abeyratne. 2005.) Determine palatal vs. non-palatal Predict treatment response Issues: Mixed results Recording, interpretation, variability, psychoacoustics Maimon & Hanly. J Clin Sleep Med 2010. 2
What are the clinical effects of primary snoring? Social annoyance Bed partners Impaired sleep quality Relationship disharmony Chronic exposure may predispose to NIHL (Sardesai. J Otolaryngol 2003.) Subjective reports do not match objective measures Snoring and Sleepiness Sleep Heart Health Cohort Study 6000 self-reported snoring and ESS ESS increases with snoring frequency and loudness Snoring and MVA Wisconsin Sleep Cohort Study PSG, self reported snoring, 5 year MVA records 374 habitual snorers (AHI <5) Gottlieb et al. Am J Respir Crit Care Med. 2000. Young et al. Sleep. 1997. 3
Snoring in Children Li et al. J Pediatr 2009. Cross-sectional study 190 non overweight children; age 6-13 PSG; Reported snoring; Awake and asleep BP monitoring Primary snoring AHI <1; snore >3 nights/week Nighttime DBP is higher Snoring in Pregnancy 1700 women: Pregnancy onset habitual snoring vs. chronic snoring Chronic snoring: Lower birth weight Elective cesarean Pregnancy onset snoring: Gestational HTN Emergent cesarean delivery No PSG O Brien et al. SLEEP 2013. Snoring and Cardiovascular risks OSA effects Initial studies linked self-reported snoring with HTN, CAD, Stroke risk. Prior to use of AHI Presumed snoring was a marker for OSA. Palomaki. Stroke. 1991. Yaggi et al. NEMJ. 2005. 4
OSA vs. Snoring and CV events Snoring and Carotid disease SLEEP 2008. 110 Subjects; Crosssectional study PSG, snoring, carotid + femoral artery doppler U/S Severe snoring (>50% sleep time) is associated with carotid but not femoralatherosclerosis AHI was not associated with CA after adjusting for snoring severity. N ~ 300 in each group Marin et al. Lancet. 2005. Adjusted for AHI - Did not examine primary snorers Pathogenesis of Snoring: Vibrations Mechanism of atherosclerosis Rabbit model Tracheotomy placed to limit hypoxia Right common carotid exposed to 6 hours of vibration Rabbit model of induced snoring Measured vibration energy of carotid wall and within the carotid lumen. Amatoury J. J Appl Physiol. 2006. Endothelial dysfunction: Reduced vasorelaxation Vibration induced vascular injury Cho et al. Sleep. 2011 5
Sound intensity and Hypertension Tracheal sound intensity in 1118 pts: nonobese, nonapneic HTN = Use of antihypertensives, or elevated BP Sleep sound intensity independently associated with elevated daytime blood pressure The Jury is out: Marin et al. Prospective cohort study with 10 year followup 377 snorers; 264 non-snorers; AHI<5 Self-reported snoring confirmed by close relative, no excessive daytime sleepiness No increased risk of fatal or nonfatal CV events in primary snorers without OSA. Nakano et al. Sleep. 2013 Marin et al. Lancet. 2005. Busselton Sleep Cohort Mortality Prospective cohort study with 17 year followup 380 pts; measure % time snoring No association with death, CV disease, stroke Marshall et al. SLEEP. 2012. Analyzed data from SNAP home sleep test Merged data from 77,000+ subjects with US social security death master file Subsample 5655 subjects without OSA: Increased snoring index (# snores/hour) is associated with a significant increase in all-cause mortality. Increased non-palatal snoring is associated with increase in mortality No information on treated OSA or comorbidities 6
Cause for Discrepancies Snoring evaluation measures No agreed standard Subjective: bed partner report, self-report Objective: sound intensity, snore time, AHI Cause for clinical effects: Snoring intensity? Sound frequency? Time spent snoring? Clinical trials required: long term effects of primary snoring? Conclusions It is difficult to diagnose OSA based on snoring alone Future study required for snoring sound analysis and objective measures of snoring. Snoring is common and may have health effects beyond social annoyance Further studies needed to examine the consequences of primary snoring and treatment outcomes. 7