Loud snoring from sleep apnea can be caused by a thick tongue, new research suggests.
Scientists have long known that losing weight can help the condition, but now they know why.
Researchers at the University of Pennsylvania say it explains why losing weight reduces the risk of obstructive sleep apnea (OSA): in turn, cutting off fat from the tongue.
Improved symptoms are linked to the slimming of the unexpected part of the body – opening the door to better treatments.
According to new research, a large tongue can be a cause of sleep apnea – but losing pounds from your body can also remove fat from your tongue, thereby treating the condition
“Most clinicians, and even experts in the world of sleep apnea, have usually not focused on fat in the tongue for the treatment of sleep apnea,” Dr. said. Richard Schwab, head of sleep medicine at the University of Pennsylvania,
It was previously assumed that having a large neck was the culprit.
“Now we know that tongue fat is a risk factor and sleep apnea improves when tongue fat is reduced, we have set a unique therapeutic goal that we have never had before,” Dr. Schwab.
It can cause people to be screened for the serious health condition – by having their tongue measured.
In sleep apnea the airways are blocked – which leads to snoring. It destroys the lives of respectively four and two percent of middle-aged men and women in the UK.
Long-term sleep apnea has been linked to a number of chronic diseases, including high blood pressure, heart disease, type 2 diabetes, stroke and depression.
When analyzing MRI scans of the throat and nose of obese patients, the researchers found reducing tongue fat the key.
The findings are based on 67 patients with mild to severe OSA with a body mass index (BMI) above 30.
Through diet or weight loss surgery, they lost on average nearly 10 percent of their weight over a six-month period.
Their throat – the part of the throat behind the mouth and nose – was scanned before and after.
Tests showed that their sleep apnea scores generally improved by 31 percent, reports the American Journal of Respiratory and Critical Care Medicine.
The researchers compared changes between overall weight loss and reductions with the volumes of the upper airway structures to identify those that led to the benefits.
They found that a reduction in the volume of the tongue fat was the most important factor. Weight loss also resulted in a smaller pterygoid – the jaw muscle that controls chewing.
Muscles on the sides of the airways – known as the pharyngeal sidewall – were also reduced
Both changes also relieved symptoms – but not to the same extent as the reduction in tongue fat.
Future studies can be set up to investigate whether certain low-fat diets are better than others in reducing tongue fat, the researchers said.
Cold therapies that use freezing temperatures to break down stomach fat can also be effective. But these theories must first be tested, said Prof. Schwab.
His team is also investigating new interventions and other risk factors for sleep apnea. Patients with large tongues that are not obese are less likely to be diagnosed.
Five years ago, they compared obese patients with and without sleep apnea and discovered that those with the condition had considerably larger and thicker tongues.
The latest findings have shed new light on the phenomenon – in all patients who suffer from snoring or drowsiness, screening for sleep apnea is required.
This is regardless of whether they appear to fall into the typical “risky” obese categories, said Prof. Schwab.
He added: “Doctors in primary care, and perhaps even dentists, should ask for snoring and drowsiness in all patients, even in patients with a normal body mass index, because based on our data they may also be at risk for sleep apnea. “
Twenty-two million Americans suffer from sleep apnea, with breathing repeatedly stopping and starting, causing patients to wake up randomly during their sleep cycle.
One of the recommended treatments is CPAP (continuous positive airway pressure), which has been free on the NHS since March 2008.
This includes wearing a mask over the nose and mouth during sleep, connected to a silent pump next to the bed. It provides light pressurized air to keep the throat open.
The mask causes breathing to return to normal during sleep and usually stops snoring for three-quarters of patients.
But for the other 25 percent who have difficulty tolerating the machine, alternative treatment options, such as oral devices or upper airway surgery, are more complicated.