Swallowing Patterns Differ Between Healthy Subjects and Patients with Sleep Apnea

In the study, Dr. Sato enrolled 10 men between the ages of 32 and 62 years with an apnea-hypopnea index that ranged from 88.1 to 39.5, who were identified with obstructive sleep apnea syndrome. They underwent studies in a sleep laboratory. Deglutition is a vital function, and the clearance of the pharynx by deglutition is important in protecting the airway, Dr. Sato said. Previously his group has reported on the patterns of human adult and child deglutition during sleep.

During sleep, deglutition was episodic, and was absent for long periods, Dr. Sato said. Deglutition did not occur during apnea or hypopnea periods. The mean number of swallows per hour during the total sleep time was 5.4 among the sleep apnea patients. The mean period of the longest absence of deglutition was 43.5 minutes.

Most deglutition occurred in association with respiratory electroencephalographic arousal after apnea or hypopnea in rapid eye movement [REM] sleep and non-REM sleep. Some deglutition occurred in association with spontaneous electroencephalographic arousal after snoring, he said.

Surface electromyography amplitude dropped to its lowest level of recording during REM sleep, Dr. Sato noted in his presentation. He also found that polysomnography showed a delay between the onset of spontaneous electroencephalography arousal and electromyography activity of deglutition.

Deglutition during sleep was infrequent and most of it-about 88 percent-occurred in association with respiratory electroencephalography arousal defined as an abrupt shift in electroencephalographic frequency after obstructive apnea, he said.

©2008 The Triological Society