Swallowing and aspiration during sleep in patients with obstructive sleep apnea versus control individuals

Abstract

Study Objectives There are only a few reports on voluntary swallowing during sleep; therefore, this study aimed to propose a method for observing voluntary swallowing during sleep using polysomnography. The frequency of voluntary swallowing during sleep and the factors related to swallowing and aspiration during sleep were investigated. Methods Polysomnography records of 20 control subjects and 60 patients with obstructive sleep apnea (OSA) (mild, moderate, and severe groups; n=20 each) were collected. Simultaneous increases in the electromyographic potentials of the submental and masseter muscles, termed co-activation, and declining oronasal airflow (SA) were extracted as “swallowing.” The cough reflex that occurred during sleep was extracted as “aspiration.” The frequency of swallowing events was compared among the different OSA severity groups. Subsequently, a multivariate regression analysis was performed. Results The average frequency of co-activation with SA in control subjects was 4.1 events/h and that without SA was 1.7 events/h. These frequencies increased with the severity of OSA during non-REM sleep. The distance of the hyoid to the Frankfurt plane was associated with the frequency of co-activation with (β=0.298, P=0.017) as well as without SA (β=0.271, P=0.038). The frequency of co-activation without SA was associated with aspiration (B=0.192, P=0.042). Conclusions Our data provide new insights into the relationship between swallowing and aspiration during sleep. We found that the longer the distance from the hyoid bone to the Frankfurt plane, the higher the co-activation without SA, which could lead to aspiration during sleep.

Screening of aspiration pneumonia using the modified Mallampati classification tool in older adults

“…In the present study, the results showed that the higher the position of the hyoid bone, the more likely it was to cause choking and cough reflex during eating and drinking. In general, it is believed that in older adults, the suprahyoid muscle group relaxes, the position of the hyoid bone decreases, and the force to pull up the hyoid bone weakens, resulting in decreased swallowing function and increased susceptibility to aspiration, often accompanied by other complications [3,6,10,21,22]; however, the results of the present study contradict this hypothesis.…”

Focus of dental sleep medicine on obstructive sleep apnea in older adults: A narrative review

“…Kohno et al examined the frequency of swallowing during sleep using the muscle activity of swallowing-related muscles as an index of swallowing and reported that it was significantly higher in patients with OSA (6.6 ± 3.8 times/h) than in those without (4.1 ± 2.2 times/h) [42]. They also focused on respiratory arrest during swallowing (swallowing apnea) and defined incomplete swallowing as swallowing activity without swallowing apnea, which was significantly more frequent in patients with OSA.…”