Alterations in the Swallowing Function According to the Severity of Obstructive Sleep Apnea Syndrome

Abstract

Objective: Obstructive sleep apnea syndrome (OSAS) is a sleep-related breathing disorder that can have a significant impact on the quality of life. According to recent studies, some OSAS patients exhibit swallowing abnormalities, such as the premature entry of food into the hypopharynx, and laryngeal penetration. We aimed to evaluate the swallowing function of OSAS patients and compare swallowing-related parameters between OSAS severity groups through a video fluoroscopic swallowing study (VFSS). Methods: Ninety-two participants with a symptom of snoring were enrolled in this retrospective study. Eighty-four participants were diagnosed with OSAS by polysomnography. The subjects were evaluated using the apnea-hypopnea index (AHI) and divided into four groups, namely non-OSAS, mild, moderate, and severe OSAS. Since all patients reported choking symptoms, they underwent VFSS and were evaluated for penetration or aspiration. The temporal parameters evaluated were oral transit time, pharyngeal transit time, and pharyngeal delay time. The movement parameters assessed were the distance, duration, and velocity of laryngeal elevation (LE). Results: Penetration was detected in six OSAS patients, but aspiration was not observed in any patient. Seventy-four patients showed vallecular and pyriform sinus residue, although the amount was not significantly large. There was no significant difference in any of the temporal parameters between the groups except pharyngeal transit time with 10 ml of yogurt. In the Pearson's correlation and multivariate linear regression analysis, LE distance and LE velocity, both correlated with AHI scores with 5 ml of liquid, 10 ml of liquid, and 10 ml of yogurt, respectively. Conclusion: Severe OSAS patients showed longer and faster hyolaryngeal movement while swallowing, which may be a compensatory movement to prevent penetration or aspiration. (JKDS 2022;12:14-23