In a small study published in the journal, Clinical Gastroenterology and Hepatology,1 researchers in Arizona tracked the sleeping patterns and esophageal pH levels of 39 individuals with gastroesophageal reflux disease (GERD), all of whom had stopped taking any GERD medications (three weeks previously for PPIs, and three days previously for H2RAs), and 9 healthy controls.
Using specialized equipment and computer software, the researchers observed that 90% of the GERD patients experienced at least one conscious awakening (defined as a period of wakefulness lasting at least two minutes, and occurring after the individual falls fully asleep), compared to 78% of the controls.
Conscious wakefulness can occur for a number of non-GERD related reasons, such as an environmental noise or the urge to urinate. An important distinction is that, of the conscious awakenings, 52% were associated with reflux in those with GERD, compared to 0% in the controls.
Interestingly, the participants only reported symptoms in 32% of the reflux-related awakenings. This points to possible flaws in the diagnostic process for nighttime GERD, as doctors rely heavily on patient reports of symptoms in diagnosing the disease. The researchers are unsure why the participants did not experience symptoms with their reflux, but propose two theories: sleep may alter perception, causing reduced sensitivity in the esophagus, or most acid reflux events, day or night, don’t express perceivable symptoms.
Another intriguing result was that 86% of acid reflux events occurred after the participants had already awoken. Once again, the study authors are not sure why this is, but offer two suggestions: either there is a stimulus that triggers arousal or awakening first, allowing reflux to occur, or the participants awoke first for a reason not related to GERD, which allowed the lower esophageal sphincter (LES) to relax, causing reflux. Also notable is that in the 14% of cases where a reflux episode began before awakening, it lasted longer than a reflux episode that began after waking.
The important information to take from this study is that nighttime GERD may lead to conscious awakenings with no observable symptoms. If you have any questions or concerns about nighttime GERD, then please discuss these with your physician.