Snoring is related to heart disease.
Snoring is a common symptom of a syndrome called obstructive sleep apnea or OSA. About 15 million Americans have OSA; this is likely an underestimate because often people are unaware of their own snoring. Besides snoring, OSA is characterized by one or more pauses in breathing during sleep. It is associated with large necks, morbid obesity and is more prevalent in men.
It was noted that 50% of patients with OSA have hypertension and that the blood pressure is harder to control without addressing the sleep apnea. OSA was also noted in more than 50% of heart failure patients, and was twice as frequent in patients with coronary artery disease (CAD) and heart attacks. In fact, more people with CAD and OSA died by 5 year follow up mark than those with CAD alone (28% versus 16%).
Heart arrhythmias are also associated with OSA. One study looked at 151 patients undergoing cardioversion for atrial fibrillation, a type of cardiac arrhythmia, and found that 49% of those patients had OSA versus 32% of control. Furthermore, a separate study found that patients with OSA who had treated their atrial fibrillation but were not treating their OSA had a greater rate of recurrence of arrhythmia, 82%, compared to patients that had been treated, with recurrence of 42%.
Mechanism
Multiple mechanisms were proposed for the association between sleep apnea and heart disease, and more studies need to be done to figure this out. One of the possibilities is that perhaps the repetitive bouts of low oxygen state during sleep apnea gives repetitive sympathetic stimulation to the nervous system, which in turn stimulates the heart and causes heart disease or arrhythmias. Another possibility is that the stimulation causes increased insulin resistance, one of the factors involved in diabetes and heart disease. Alternatively, it may be secondary to development of vasoactive substances, such as endothelin or leptin, which were noticed in both cardiovascular diseases and sleep apnea.
Diagnosis
Obstructive sleep apnea is diagnosed with a sleep study. A sleep study is done at specialized centers where they are able to observe people sleep and use devices that measure various variables like air pressure, blood oxygen, respiratory effort to distinguish between OSA and many other sleep disturbances.
Treatment
Treatment of OSA depends on the severity of the disease. Treatment may involve weight loss, medical devices, such as continuous positive airway pressure (CPAP) that allow to splint and keep open the airway to prevent the apnea, or surgery. Surgery is usually reserved for people who have failed other interventions.
References
Chung MK. Atrial fibrillation, sleep apnea and obesity. Nature clinical practice cardiovascular medicine 2004. 1: 56-59.
Gami ASS. Association of atrial fibrillation and obstructive sleep apnea. Circulation 2004. 110: 364-367
Kanagala et al. Obstructive sleep apnea and recurrence of atrial fibrillation. Circulation 2003. 107: 2589.
Somers VA. Sleep apnea and cardiovascular diseases. Circulation 2008. online Jul 28, 2008. DOI: 10.1161/CIRCULATIONAHA.107.189420.
October 20, 2008
Posted on October 20, 2008
