ESOPHAGEAL MOTOR DYSFUNCTION AND ACID EXPOSURE IN REFLUX ESOPHAGITIS ARE MORE SEVERE IF BARRETTS METAPLASIA IS PRESENT

Objectives: To compare esophageal motor function in patients with refl ux esophagitis with controls, and to identify patient characteristics that may have a bearing on the severity of esophageal motor dysfunctio n and acid exposure. Methods: Esophageal motor function was assessed i n 60 patients with reflux esophagitis. All patients had manometry, 50 had an esophageal transit test, and 23 had an acid clearance test. For ty-eight had dual site [5 and 10 cm above lower esophageal sphincter ( LES)] esophageal pH monitoring, four had only distal pH monitoring, an d one patient had only proximal pH monitoring. Thirty-four controls un derwent the same tests. The association between the indices of esophag eal function plus the degree of esophageal acid exposure and eight pat ient characteristics (age, sex, obesity, smoking, alcohol intake, hiat us hernia, grade of esophagitis, and Barrett's metaplasia) was examine d in unifactorial and multifactorial analysis of variance. Results: Th e patients had significantly lower LES pressure, lower distal and midd le esophageal amplitudes, longer duration of contraction, and slower v elocity of propagation. They had longer esophageal transit and acid cl earance times. Barrett's metaplasia was the only factor that had an as sociation with the magnitude of esophageal motor dysfunction and acid exposure, except age, which had a weak positive association with acid exposure (p = 0.03). Compared to the rest of the patients with esophag itis, patients with Barrett's had lower LES pressure (median = 10.5 vs . 17.5 mm Hg, p = 0.013), longer supine transit time (median = 180 vs. 13.5 s, p = 0.0001), and higher % of total time pH < 4 (median = 48.2 vs. 8.7 and 23.2 vs. 5.2; p < 0.0001 for distal and proximal esophage al acid exposure, respectively). Ten of the 12 patients with Barrett's had abnormal manometry, compared with 20 of the 48 without (chi(2) = 6.67; p < 0.01). There was a strong correlation between the degree of acid exposure in the proximal esophagus and the length of Barrett's se gment (r = 0.846, 0.81, 0.725; and p < 0.001, 0.005, 0.018, for the % of times pH < 4 for total, supine, and upright periods, respectively). Conclusions: The development of Barrett's metaplasia may be determine d by the degree of esophageal exposure to the refluxate which, in turn , may be a function of the severity of esophageal motor dysfunction. T he length of Barrett's segment may be dependent on the extent of orad transport of the refluxate.