Scientists prove effectiveness of mouth exercises to combat snoring

Protocol reduces snoring frequency and intensity by reducing flaccidity of throat muscles.

By Karina Toledo

Agência FAPESP – In an article published in the journal Chest, Brazilian researchers show that six simple daily exercises derived from traditional speech-therapy techniques can reduce the frequency and intensity of snoring when performed with guidance from a specialist. They also found that the exercises can alleviate mild to moderate obstructive sleep apnea (OSA) and prevent progression of the disease.

The project was led by pulmonologist Geraldo Lorenzi Filho at the Sleep Laboratory of the University of São Paulo’s Heart Institute (INCOR-USP), with FAPESP’s support.

“Even though it’s a great nuisance and can be associated with a certain social stigma, snoring hasn’t received much medical attention except in cases of OSA, and there have been no objective measures of snoring intensity in OSA diagnostic tests,” Lorenzi Filho told Agência FAPESP.

Snoring is caused by tissue and muscle vibration when air passes through the upper airway and by natural relaxation of the throat muscles during sleep, Lorenzi Filho explained. Anatomical characteristics can predispose some individuals to the problem, which tends to worsen with age owing to increasing flaccidity of the throat muscles and which tends to be more common in overweight individuals, who accumulate fatty tissue that obstructs the passage of air in the neck and throat.

“We believe pharyngeal tissue vibration over the years also contributes to increased muscle flaccidity and hence aggravates snoring,” Lorenzi Filho said. “This means people who don’t have OSA may develop the disease if they do nothing to combat snoring. These exercises could possibly be a form of prevention.”

Considered a major risk factor for heart disease, OSA is characterized by recurring partial or total obstruction of the upper airway during the night, as a result of which breathing may stop for at least ten seconds in adults. Snoring is estimated to be present in between 70% and 95% of cases.

“OSA is diagnosed by polysomnography, but snoring is neither measured nor taken into account in the diagnosis,” Lorenzi Filho said. Polysomnography is a comprehensive recording of the biophysiological changes that occur during sleep, such as brain activity, eye movements, heart rhythm and respiratory airflow, using electrodes attached to the patient.

In partnership with Adriano Alencar, a researcher affiliated with the University of São Paulo’s Physics Institute (IF-USP), Lorenzi Filho’s group standardized a method for measuring total snoring noise during the night. This measure was the basis for evaluating the effectiveness of the exercises.

In the standardized method developed by the group, a device continuously records a patient’s snoring during polysomnography and analyzes the snoring intensity and frequency (the number of episodes during the night).

Randomized trial

The study included a randomized trial in 39 patients of both sexes. All complained of snoring; some had associated OSA and others had mild or moderate OSA. Their ages ranged between 20 and 65. Nineteen volunteers practiced the exercise protocol developed at INCOR-USP. The other 20 patients acted as a control group, performing only respiratory exercises that did not specifically target the muscles in the region where snoring is produced.

The patients were assessed after three months of treatment. The group submitted to the exercise protocol displayed a small reduction in neck circumference, associated with a 36% decrease in the number of snoring episodes per night and a 60% drop in total noise production. The results for the control group were the same as those in the pre-treatment assessment.

“The exercises tested in the study were adapted from a procedure used in a specialized field of speech therapy called orofacial motricity,” said Vanessa Ieto, a member of the Sleep Laboratory team and first author of the article.

In a paper published in 2009 on research led by Kátia Guimarães for her PhD thesis, the group had already shown that a set of 13 exercises designed to stimulate orofacial motricity was capable of reducing the severity of sleep apnea. Snoring was measured only subjectively in this first study, by means of a questionnaire.

“For this latest study, however, we simplified the technique to improve adherence to the treatment,” Ieto explained. “We selected the six exercises that most mobilize the muscles in the region where snoring is produced: the soft palate at the back of the roof of the mouth, the uvula, and the underside of the tongue. We measured the reduction in snoring objectively and also by means of a questionnaire.”

Although the exercises are easy to perform and have no contraindications, they should be prescribed and supervised by a specialist in orofacial motricity, Ieto stressed.

“After a prior assessment, initial therapy is prescribed,” she said. “As the patient progresses, we increase the number of repetitions and the degree of difficulty. If the exercises are done incorrectly, they won’t produce the desired result.”

Before treatment begins, a specialist in sleep medicine should perform an assessment to see whether the patient has OSA associated with the snoring and, if so, how severe it is.

“In the case of severe OSA, the treatment is different. A diagnosis is required first and foremost,” Ieto said.

Estimates by INCOR-USP suggest that 54% of the adult population suffers from snoring, with higher prevalence among obese males, the elderly, and postmenopausal women. In addition to orofacial motricity exercises, other ways of combating snoring noted by Lorenzi Filho include weight control, avoiding consumption of alcohol and sedatives before sleeping because they relax the throat muscles, and not sleeping on one’s back because in this position the tongue tends to obstruct the airway.