Acidic and non-acidic reflux during sleep under conditions of powerful acid suppression

During sleep, individuals are uniquely vulnerable to acid reflux. Acid reflux during sleep has been studied by a number of investigators, but non-acid reflux is largely unexplored.

In this study, 15 individuals with significant subjective complaints of heartburn were treated with esomeprazole, 40 mg bid, and with placebo, in random order, for 1 week each. After 1 week of treatment, participants underwent combined impedence/pH monitoring and polysomnography. In both drug and placebo conditions, these procedures were done after participants consumed a meal designed to increase the likelihood of reflux events.

Total reflux events and acid reflux events were significantly decreased with proton-pump inhibitor (PPI) treatment as compared to placebo. Nonacid reflux events were more common with PPI treatment as compared to placebo, but this result was not statistically significant. The ratio of non-acidic to acidic events was significantly greater with PPI treatment, however. Similar results were found for reflux events that occurred only during sleep. Proximal migration of acidic vs non-acidic reflux events was found to be similar. There was no difference in sleep architecture between placebo and drug conditions.

PPI treatment reduced overall reflux events, but non-acidic reflux events were relatively more likely to occur with PPI treatment. The occurrence of these non-acidic reflux events on PPI might conceivably explain why some individuals continue to have symptoms after PPI treatment.