Objective: Gastroesophageal reflux disease (GERD) and obstructive sleep apnea (OSA) often coexist. We sought to determine the presence and direction of any association between GERD and sleep events in patients with OSA.
Materials and methods: We conducted a case-crossover study among 18 patients with known OSA and GERD. All study patients underwent overnight simultaneous polysomnography and esophageal pH monitoring. A series of case-crossover analyses was conducted by defining each of the sleep (i.e. arousal, awakening, and apnea) and gastroesophageal reflux (GER) events as the outcome in turn. Respective control time points were randomly selected in all eligible control periods. When a sleep event was the outcome, the GER event was the exposure of interest. When GER was the outcome, each sleep event was assessed as the exposure individually. Conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
Results: Both awakenings and arousals were significantly associated with the subsequent onset of a GER event. The OR for a GER event following an awakening was 5 (95% CI 3.6-6.9) and for a GER event following an arousal was 2.5 (95% CI 1.8-3.4). Apnea did not lead to GER (OR 1.0, 95% CI 0.8-1.4). GER was not more commonly observed before any of the sleep events compared with control periods without sleep events.
Conclusion: In patients with coexisting GERD and OSA, both awakening and arousal preceded GER events, but GER does not appear to precipitate sleep-related events.