Gastric motility and autonomic activity during obstructive sleep apnea

Abstract

Summary Background Patients with Obstructive Sleep Apnea Syndrome (OSAS) often experience gastroesophageal reflux disease (GERD). Aim To investigate gastric motility and autonomic nervous activity during sleep apnea. Methods The subjects of this study were 20 individuals with OSAS who experienced 10 or more sleep apnoea events per hour, as measured with a portable sleep polygraph. A percutaneous electrogastrography (EGG) and fast Fourier transformation analysis was carried out on the results. The mean amplitude was compared for bradygastria, normogastria and tachygastria. Spectral analysis of heart rate variability was performed, and low‐frequency (LF) power, high‐frequency (HF) power and the LF/HF ratio were measured. Oesophagogastroduodenal endoscopy was performed on each subject, and the presence of reflux oesophagitis (RE) was diagnosed according to the Los Angeles (LA) grade classification. Moreover, questionnaire for the diagnosis of reflux disease (QUEST) was carried out. Results Normogastria was significantly decreased, and brady‐, tachygastria, or both were increased during sleep apnea (P < 0.01). There was no significant relation between LA grade classification of RE and severity of OSAS. The LF/HF ratio was significantly higher during sleep apnea for patients with RE and OSAS, but the opposite for those with RE without OSAS. Decreased percutaneous arterial oxygen saturation and normogastria were independent risk factors for the severity of RE. Conclusions The present study suggested that, in addition to decreased pressure on the pleural cavity, factors affecting the development of RE might include abnormal gastric motility, low oxygen, and increased sympathetic nervous activity during sleep apnea.

Mechanisms of nocturnal gastroesophageal reflux events in obstructive sleep apnea

“…This is a very similar pattern to that reported by other studies in patients with reflux disease without OSA [16,40], suggesting that the mechanisms of nocturnal GER are no different in those with OSA relative to those without. Finally, the frequency of TLESR when off CPAP (1.2±0.4 per hour) was similar to that previously reported in healthy subjects and patients with GER disease without OSA (0.5-3.7 per hour) [29,41], suggesting that apnea-associated increased parasympathetic (vagal) nervous activity [42] has a minimal, if any, role in the genesis of TLESR and nocturnal GER in patients with OSA.…”