When the lining of the two blood vessels that nourish the brain with oxygen-rich blood thicken, it is usually the first step towards the development of atherosclerosis (hardening of the arteries), the researchers explained. Atherosclerosis causes several vascular diseases.
The left and right common carotid arteries supply the head and neck with oxygenated blood - they divide the neck to form the external and internal carotid arteries.
Lead study author Robert Deeb, M.D., said:
"Snoring is more than a bedtime annoyance and it shouldn't be ignored. Patients need to seek treatment in the same way they would if they had sleep apnea, high blood pressure or other risk factors for cardiovascular disease.
Our study adds to the growing body of evidence suggesting that isolated snoring may not be as benign as first suspected. So instead of kicking your snoring bed partner out of the room or spending sleepless nights elbowing him or her, seek out medical treatment for the snorer."
The researchers found that snorers, including those with no sleep apnea, had alterations in the carotid artery. They believe the changes are most likely caused by trauma and subsequent inflammation that the snoring vibrations cause.
The scientists presented their findings at the 2013 Combined Sections Meeting of the Triological Society in Scottsdale, Arizona. They also submitted their research to The Laryngoscope for publication.
Research findings on snoring have been contradictoryIn October 2012, researchers from the Woolcock Institute of Medical Research, Australia, found that snoring is not a risk factor for cardiovascular disease or mortality, regardless of whether or not the person has sleep apnea. They added that those who snore every night are not more likely to die within the next seventeen years than relatively infrequent snorers.
Hungarian researchers in 2008 reported in the journal Sleep that loud snorers are considerably more likely to develop stroke and heart disease compared to those who never or very rarely snore. Their study, involving 12,643 Hungarian adults, found that about 40% of males and 24% of females snore regularly.
Snoring causes cardiovascular disease, long before OSA doesOSA (obstructive sleep apnea) has been linked to the development of cardiovascular disease, as well as some other illnesses.
The scientists believe that for cardiovascular disease, the problem probably starts with snoring, long before OSA sets in. So far, very few studies have demonstrated an association between snoring and cardiovascular disease risk.
Dr. Deeb along with senior study author Kathleen Yaremchuk, M.D. gathered and examined data on 913 patients who had been evaluated by the Henry Ford Hospital's sleep center. The patients had taken part in a diagnostic sleep study from December 2006 to January 2012. They were aged from 18 to 50 years; none of them had sleep apnea at baseline.
Fifty-four of the patients completed the snore outcomes survey which examined their snoring habits. They had also undergone a carotid artery duplex ultrasound to determine how thick the intima-media of their carotid arteries were.
Carotid intima-media thickness is a measurement of the two innermost layers of the arterial wall, and can be used to determine whether there is any atherosclerotic disease. If the intima-media is too thick, it is usually an initial sign of carotid artery disease.
There was no considerable difference in intima-media thickness between patients with traditional cardiovascular disease risk factors and those without. Risk factors for cardiovascular disease include high blood pressure (hypertension), high blood cholesterol (hypercholesterolemia), smoking and diabetes.
Dr. Deeb said:
"Snoring is generally regarded as a cosmetic issue by health insurance, requiring significant out-of-pocket expenses by patients. We're hoping to change that thinking so patients can get the early treatment they need, before more serious health issues arise."
The team plan to carry out another long term study on people who snore during their sleep. They say they will focus on whether there is a link between cardiovascular event rates and snoring.
The study was funded by the Henry Ford Hospital.
What are the causes of snoring?Snoring occurs when the soft tissue at the back of a person's head and neck vibrates as they breathe in.
The following tissue may be affected:
- the nasal passages
- the soft palate - the soft tissue at the back of the roof of the mouth
- the base of the tongue
- the tonsils
- the uvula - a soft section of tissue that hangs from the soft palate between a person's tonsils
The same can occur when the airways are partially blocked, as may be the case with enlarged tonsils or when somebody has a cold.
Doctors say that snoring typically gets worse over time if it is not treated. The muscles gradually get weaker, making it harder to keep the airways open, resulting in even more frequent and louder snoring.
The following situations, illnesses and conditions are linked to a higher risk of habitual snoring:
- Being obese - especially if there is a lot of fat around the person's neck.
- Alcohol - when we drink alcohol our muscles relax
- Some antidepressants and sedatives - some of these drugs relax the muscles, raising the risk of snoring
- Tobacco smoking - the airways are more likely to become inflamed, making them narrower, resulting in snoring
- Allergic rhinitis - when the inside of the nose swells up because of an allergic reaction. Dust or pollen (hay fever) are common examples of allergic rhinitis