Results of 24-hour esophageal impedance-pH monitoring in 141 patients with gastroesophageal reflux disease

Objective To analyze the relationship between body type, age, gender, esophageal motility function, lower esophageal sphincter pressure (LESP) and clinical classification and type of reflux contents of patients with gastroesophageal reflux disease (GERD). Methods From September 2015 to July 2016, at Beijing Tongren Hospital of China Capital Medical University, the results of 24-hour esophageal impedance-pH monitoring of 141 patients with GERD were retrospectively analyzed. The differences of reflux contents were compared in patients with GERD among different body type, age, gender, esophageal motility function, LESP and clinical classification. Mann-Whitney test was performed for comparison between groups. Results Acid reflux was more common in obese patients (body mass index more than 23.9 kg/m2) compared with patients with normal body type (body mass index from 18.5 to 23.9 kg/m2) (18.5, 7.0 to 45.3 vs. 10.0, 2.0 to 32.0), and the difference was statistically significant (Z=-2.320, P=0.020). Patients under 65 years old had more numbers of weak acid reflux, non-acid reflux and gas reflux than patients over 65 years old (58.5, 32.8 to 95.0 vs. 40.0, 24.0 to 71.0; 19.5, 6.0 to 47.5 vs. 8.0, 3.0 to 19.0; 46.0, 23.8 to 79.3 vs. 35.0, 11.0 to 56.0), and the differences were statistically significant (Z=-2.690, -3.286 and -2.091, all P 0.05). Patients with reflux esophagitis(RE)and /or Barrett′s esophagus (BE) had more weak acid reflux, non-acid reflux and gas reflux compared with patients with non-erosive reflux disease (NERD) (61.0, 31.3 to 102.5 vs. 44.0, 24.5 to 66.5; 18.0, 8.0 to 36.5 vs. 8.0, 2.0 to 22.0; 49.5, 27.5 to 86.5 vs. 26.0, 11.0 to 47.0), and the differences were statistically significant (Z=-2.585, -2.942 and -3.278, all P<0.05). Patients with lower esophageal sphincter (LES) relaxation were more likely to have weak acid reflux than patients with normal LES function (57.0, 32.3 to 87.0 vs. 40.0, 21.0 to 73.0), the difference was statistically significant (Z=-2.065, P=0.039). Conclusion Body type, age, gender, LESP and clinical classification are related to type of reflux contents in GERD patients, while esophageal peristalsis is irrelevant. Key words: Gastroesophageal reflux; 24-hour esophageal impedance pH monitoring; Patterns of reflux episodes