The relationship between gastroesophageal reflux disease and obstructive sleep apnea.

There has been an accumulating body of research concerning the extraesophageal complications of gastroesophageal reflux disease over the past decade. Given the cardiological, pulmonological, laryngeal, and dental aspects of such complications, an interdisciplinary approach is required. The most recognized manifestations are noncardiac chest pain, bronchial asthma, chronic bronchitis, chronic cough, and posterior laryngitis, as well as the acidic damage of dental enamel. This article focuses on the potential relationship between reflux disease and obstructive sleep apnea, which has been raised only more recently. Because of the decrease of primary peristalsis and the reduced production of saliva, as well as the diminished acid and volume clearance of the esophagus, sleeping can be considered as a risk factor of the reflux event by itself. Moreover, it should also be taken into account that the transdiphragmatic pressure increases in parallel with the growing intrathoracic pressure generated during obstructive apnea episodes. This has a non-negligible effect on the phrenoesophageal ligament, which is connected to the lower esophageal sphincter. Repetition of the pressure changes results in insufficiency of the cardia. While this pressure change produces a considerable suction effect, further reducing the clearing mechanism of the gastric volume, lower esophageal sphincter insufficiency can directly lead to reflux disease. The challenge for gastroenterologists is to gain further insight into this relationship and to play a more active role in the complex therapy of the disease, as well as to develop a new diagnostic approach towards the severe forms of gastroesophageal reflux disease.