Association Between Obstructive Sleep Apnea and Gastroesophageal Reflux Adjusted for Obesity in Patients With Sleep Disorders: a Case-control Study

Abstract Background: The association between obstructive sleep apnea syndrome (OSAS) and gastroesophageal reflux disease has been reported in multiple studies and meta-analyses. Although obesity has been cited as a common risk factor for both conditions, in Far East Asia, sleep apnea is often attributed to craniofacial anatomy, and patients with obstructive sleep apnea are not necessarily obese. In the present study, we investigated whether there is an association between obstructive sleep apnea and gastroesophageal reflux after adjusting for obesity.Method: The subjects were 230 patients with sleep disorders who visited the Sleep Center at Osaka Kaisei Hospital between May 2016 and November 2017. All patients underwent esophagogastroduodenoscopy. They were diagnosed with sleep disorders by a respiratory specialist, and all patients with suspected OSAS underwent polysomnography/portable monitoring. BMI was measured from the height and weight of all patients, and they were categorized into three groups: non-obese OSAS, obese OSAS, and control (non-OSAS). The presence or absence of reflux esophagitis in each group was compared using the Los Angeles classification.Results: There were 138 patients in the obese OSAS group, 71 patients in the non-obese OSAS group, and 21 patients in the control group. There was a greater prevalence of reflux esophagitis both in the obese and non-obese OSAS groups compared with the control group (both p<0.05). Multivariate logistic regression analysis including other factors showed that alcohol consumption was the most significant factor in the non-obese OSAS group (p<0.05), but the severity of OSAS as measured by the Apnea-hypopnea Index was not a significant factor (p=0.64).Conclusions: In patients with sleep disorders, OSAS is associated with gastroesophageal reflux regardless of obesity. Alcohol consumption is also a major factor in non-obese patients with OSAS. Since alcohol consumption is associated with the risk of esophageal squamous cell carcinoma and gastroesophageal reflux is associated with the risk of esophageal adenocarcinoma, regular upper gastrointestinal endoscopy is thought to be necessary in patients at risk.