Snoring is Bad for the Heart? Not so fast...

This past week, media has both aired and published a story regarding new research that suggests snoring WITHOUT obstructive sleep apnea may lead to potential increased risk of heart disease as well as stroke.

Apparently, researchers in Michigan examined the data of 913 patients between the ages of 18 and 50 who had undergone a sleep study between 2006 and 2012. None had been diagnosed with sleep apnea, but did have significant snoring. These patients underwent an ultrasound that measured the thickness of the carotid artery inner lining. The thicker the inner lining of the carotid artery, the higher the risk for carotid artery disease and stroke.

The researchers found that in their patient population, the carotid arteries were thicker in snorers than in non-snorers. In fact, these abnormal changes were comparable to smokers, diabetics, and patients with hypertension.

Unfortunately, their findings have not yet been published (though submitted to the journal Laryngoscope), but was presented at the Combined Sections Meeting of the Triological Society in Scottsdale, Arizona held between January 24-26, 2013.

However, this is not the first study to show a link between snoring and heart disease. Hungarian researchers in 2008 reported that loud snorers were at significantly higher risk for stroke and heart disease in their study population of 12,642 subjects.

Contradictory Research: Snoring is NOT Bad for the Heart

Now, before every snorer goes into a panic regarding the fact that they snore, even if there are no problems with obstructive sleep apnea confirmed on sleep study, consider this...

Australian researchers published findings in 2012 that snoring did NOT increase risk for heart disease and mortality regardless of whether the patient suffered from sleep apnea or not. Their population study group consisted of 380 subjects.


What's Going On?

Admittedly, the burden of epidemiological evidence does suggest a link between snoring alone and potential increased risks for stroke and heart disease. But the very factors that predispose to snoring are also associated with other diseases that confound a conclusive relationship. Such other confounding factors include obesity, hypertension, diet, age, smoking, and alcohol consumption. When ignoring snoring-related health issues, there are numerous other confounding factors including periodontal disease, personality, stress, sedentary lifestyle, etc.

A study I would like to see to help clear the confusion regarding the risk of snoring would be to examine a large population of subjects who snore, but who are all skinny, non-smokers, non-alcohol drinkers, not diabetic, do not have high blood pressure, eat a balanced healthy diet, do not have a type A personality, good teeth, exercise daily, and lead a relatively stress-free life.

Any takers???

Assuming Snoring DOES Lead to Elevated Risk

The simplistic reason this may occur is due to acoustic and vibrational trauma that gets transmitted from the airway to the carotid arteries located nearby in the neck. Such snore-induced vibrational trauma leads to micro-injury to the inner lining of the carotid artery leading to thickening.

With thickening, the carotid arteries in essence become more narrow leading to increased risk of stroke.

Such vascular injury can also lead to increased levels of catecholamines that can lead to similar changes elsewhere in the body including the heart.

Of course, there are more complex variables at play which requires more complex answers, but that's beyond the scope of this blog.

Treatment

Snoring is unfortunately a complex problem to fix and does require some testing to fully evaluate and treat successfully. Such tests include fiberoptic laryngoscopy, sleep study and sedated endoscopy.

Source:
Snoring May Be as Bad as Smoking for Your Heart. Medical Daily 1/24/13

References:
Cardiovascular Disease and Health-Care Utilization in Snorers: a Population Survey. Sleep 2008 Mar;31(3):411-6.

Snoring Is Not Associated With All-Cause Mortality, Incident Cardiovascular Disease, or Stroke in the Busselton Health Study. Sleep. 2012 Sep 1;35(9):1235-40. doi: 10.5665/sleep.2076.