Sleep apnea is a common disorder affecting 22 million Americans, halting their breath suddenly and randomly throughout the night. While there are machines and devices that can help prevent these dangerous pauses, research has shown that avoiding weight gain is one of the primary ways to reduce their severity. New research has now zeroed in on the finer details of this physiological effect, revealing that a reduction of fat in the tongue appears key to lessening sleep apnea's symptoms.
The research was carried out by scientists at the University of Pennsylvania, and built on one of their earlier studies comparing tongue size and fat content among obese patients with and without sleep apnea. That 2014 study found that those with sleep apnea possessed larger tongues with higher fat content, so the researchers began to investigate whether reducing that fat content could alleviate the symptoms of the condition.
Sixty-seven subjects were enlisted for the latest study, all obese with mild to severe sleep apnea. On average, the subjects lost 10 percent of their body fat over a six-month period, either through weight loss surgery or diet, with their sleep apnea scores improving by an average of 31 percent as assessed by a sleep study.
The scientists performed MRI scans on the pharynx and abdomens both before and after, with the team then assessing how overall weight loss influenced the volume of different structures in the upper airway, and in turn how that influenced the severity of the sleep apnea symptoms. Their analysis found that a reduction in tongue fat volume to be the "primary link" between weight loss and sleep apnea symptoms.
“Most clinicians, and even experts in the sleep apnea world, have not typically focused on fat in the tongue for treating sleep apnea,” says co-author Richard Schwab, chief of Sleep Medicine at the University of Pennsylvania. “Now that we know tongue fat is a risk factor and that sleep apnea improves when tongue fat is reduced, we have established a unique therapeutic target that we’ve never had before.”
From here, the researchers would like to conduct follow-up studies exploring how some low-fat diets could be tuned specifically to lower fat content in the tongue, as well as some alternative approaches such as cold therapy. Further to this, the team is also looking into the possibility that some patients might have fat tongues but are not obese, and are therefore susceptible to sleep apnea without some of the traditional tell-tale signs.
The research was published in the American Journal of Respiratory and Critical Care Medicine.
Source: University of Pennsylvania