Comparison of Acid Reflux Characteristics throughout the Sleep Period among the Different Gastroesophageal Reflux Disease (GERD) Groups

Abstract

Purpose: To compare extent of esophageal acid exposure during sleep time among patients with non-erosive reflux disease (NERD) and abnormal pH test, erosive esophagitis (EE) and Barrett's esophagus (BE). Methods: Consecutive patients who underwent 24-h esophageal pH testing off proton pump inhibitors for GERD were enrolled. The extent of esophageal acid exposure was assessed every two hours of the sleep period (0–2, 2–4, 4–6, 6–8 hrs.). Each period of two hours was evaluated for the mean total number of acid reflux events, mean duration of an acid reflux event (in minutes), mean frequency of acid reflux events (per hour) and mean percentage time pH < 4 (in minutes). Results: A total of 50 GERD patients were enrolled (NERD - 20, EE - 17, BE - 13). Mean age and gender were similar among the different GERD groups (mean age and M/F ratio for EE, NERD and BE were: 62, 52, 62, and 15/2, 15/5, 12/1, respectively). The mean time (minutes) elapsed from the last meal before the onset of sleep among the GERD groups: BE: 152, EE: 125, NERD: 92 (p= NS). All 3 groups demonstrated a decline in esophageal acid exposure throughout the sleep period as assessed by the 4 sleep intervals. Mean percent time pH < 4 in BE: 32.3, 49.0, 29.2, 2.4; EE: 11.9, 11.5, 7.1, 7.7 and NERD: 9.7, 9.1, 4.0, 2.3 (all p < 0.05). Mean number of reflux events in BE: 16.2, 15.4, 10.9, 8.9; EE: 7.1, 3.5, 3.2, 4.4 and NERD: 8.1, 6.6, 2.3, 3.5 (all p < 0.05). Mean frequency (per hour) of acid reflux events in BE: 8.1, 7.7, 4.1, 4.1; EE: 3.6, 1.8, 1.6, 2.2 and NERD: 4.1, 3.1, 1.2, 1.8 (all p < 0.05). All GERD groups demonstrated a significantly higher esophageal acid exposure in the first versus second half of the sleep period as assessed by the mean percent time pH < 4 (BE: 40.6 vs.15.7, EE: 11.7 vs. 7.4, NERD: 9.2 vs. 3.1, all p < 0.05). Patients with BE had a significantly higher distribution of esophageal acid exposure throughout the sleep period as compared to those with NERD and EE (p < 0.05). There was no statistical difference in esophageal acid exposure during the different sleep intervals between patients with NERD and those with EE (p= NS). Conclusions: Esophageal acid exposure declines during the sleep period regardless of the GERD group. Patients with BE demonstrated the greatest decline during sleep period. There is no difference in esophageal acid exposure during sleep period between EE and NERD (with abnormal pH test) patients.