Swallowing in Obese Individuals before and after Bariatric Surgery

Altered swallowing biomechanics in people with moderate-severe obstructive sleep apnea

STUDY OBJECTIVES

Dysphagia is a common but under-recognized complication of obstructive sleep apnea (OSA). However, the mechanisms remain poorly described. Accordingly, the aim of this study was to assess swallowing symptoms and use high-resolution pharyngeal manometry (HRPM) to quantify swallowing biomechanics in patients with moderate-severe OSA.

METHODS

Nineteen adults (4 female, mean age 46±26-68y) with moderate-severe OSA underwent HRPM testing with 5,10 & 20 ml volumes of thin and extremely thick liquids. Data were compared to 19 age- and sex-matched healthy controls (mean age 46±27-68y). Symptomatic dysphagia was assessed using the Sydney Swallow Questionnaire (SSQ). Swallow metrics were analyzed using the online application swallowgateway.com. General linear mixed model analysis was performed to investigate potential differences between people with moderate-severe OSA and controls. Data presented are means (95% CI).

RESULTS

26% (5/19) of the OSA group but none of the controls reported symptomatic dysphagia (SSQ>234). Compared to healthy controls, the OSA group had increased upper esophageal sphincter (UES) relaxation pressure (-2 [-1] vs. 2 [1]mmHg, F = 32.1, p <0.0001), reduced UES opening (6 vs. 5mS, F = 23.6, p<0.0001) and increased hypopharyngeal intrabolus pressure (2 [1] vs 7 [1]mmHg, F= 19.0, p <0.05). Additionally, upper pharyngeal pressures were higher, particularly at the velopharynx (88 [12] vs. 144 [12]mmHg.cm.s, F = 69.6, p<0.0001).

CONCLUSIONS

HRPM identified altered swallowing biomechanics in people with moderate-severe OSA, which is consistent with a subclinical presentation. Potential contributing mechanisms include UES dysfunction with associated upstream changes of increased hypopharyngeal distension pressure and velopharyngeal contractility.