Background: Prolonged (96 h) pH monitoring may explore the effect of diet on pH and symptoms in patients with GERD.
Aims: To assess the usefulness of a 96 h esophageal pH study in patients with GER symptoms under different diets (pro- and anti-GER).
Methods: Prospective study of 66 patients with GERD undergoing wireless 96 h pH monitoring. Two-day periods, one on liberal (pro-reflux) and another on restricted (anti-reflux) diet assessed esophageal acid exposure and symptoms. The primary end point was normalization of acid exposure time while on restricted diet. Secondary end point was a > 50% reduction in symptoms with restricted diet.
Results: Normal (pH time < 4 of < 6%) was found in 34 patients (51.5%) while on the initial 48 h (liberal) diet [median % time < 4: 3.2 (95% CI, 1.9, 4.0)] and remained normal while on restricted diet [median % time < 4: 2.6 (95% CI, 0.8, 3.4)]. Abnormal acid exposure (% pH time < 4: > 6%) was found in 32 patients (48.5%) while on initial 48 h liberal diet [median % time < 4: 10.5, (95% CI 8.9, 12.6)], and decreased significantly with restricted diet [median % time < 4: 4.5 (95% CI 3.1, 7.3)] (p = 0.001), and normalized with anti-GERD diet in 21 patients (65.6%). Only 11/66 patients were candidates for proton pump inhibitor (PPI) use; 34 had either normal pH studies or normalized them with restricted diet (n = 21). Symptoms did not improve with restricted diet.
Conclusions: The 96-h esophageal pH study tests for GERD under pro- and anti-GER diets and allows minimization of PPI therapy to only 16.6% of patients.
Keywords: Diet; Esophageal ambulatory pH monitoring; Gastroesophageal reflux disease (GERD); High-resolution impedance manometry (HRM); Proton pump inhibitors (PPI).