Nocturnal reflux symptoms correlate with respiratory events in patients with obstructive sleep apnea

Abstract

Background: Both obstructive sleep apnea (OSA) and gastro-esophageal reflux disease (GERD) are common diseases that share similar risk factors. There have been ongoing controversies regarding the role of gastro-esophageal reflux (GER) in obstructive sleep apnea (OSA). Aims: To determine whether the presence and the severity of GERD is related to the severity of OSA. Methods: Consecutive patients with OSA diagnosed on polysomnography (PSG) (defined as respiratory distress (RDI) index >5) were recruited. Subjects completed a validated GERD questionnaire. The presence and the severity of nocturnal reflux were also assessed. Results: A total of 47 cases were recruited. The median RDI was 17.3 (range 5.1-63.1). The median arousal per hour was 23.5 (range 4.1 to 62.2). BMI positively correlated with RDI (r=0.606, p<0.001) but not with the number of arousals (p=0.201). No correlation was found between the presence of GERD and RDI (p=0.622) or number of arousals per hour (p=0.557). The severity of GERD did not correlate with both RDI (p=0.551) or number of arousals per hour (p=0.451). However, the severity of nocturnal reflux correlated with the number of arousals per hour (r=0.299, p=0.048). The severity of nocturnal reflux was also linked to RDI but it did not reach statistical significance (r= 0.293, p=0.054). Conclusions: This study demonstrated that nocturnal reflux appeared to affect sleep quality and contribute to the severity of sleep apnea. It is possible that the conflicting results of OSA and GERD from the current literature is that the population studied may not all have nocturnal GERD. Further study in this area should focus on patients that complain of nocturnal reflux.