Characteristics of acid reflux of 200 patients with gastroesophageal reflux disease in upright position, supine position and postprandial period / 中华消化杂志

ABSTRACT

Objective:To analyze the reflux parameters of patients with gastroesophageal reflux disease (GERD) in upright position, supine position and at 2 h after meals, and to explore the cut-off value, sensitivity and specificity of the reflux parameters in different positions and at 2 h after meals in GERD diagnosis.Methods:From January 2016 to July 2020, 200 GERD patients (GERD group) and 61 non-GERD patients (control group) who visited Huazhong University of Science and Technology Union Shenzhen Hospital (Former Nanshan District People′s Hospital), were selected. All the patients of the two groups received gastroesophageal reflux disease questionnaire (GERDQ), upper gastrointestinal endoscopy, esophageal high resolution manometry and 24 h esophageal pH combined impedance monitoring. T test, non-parametric test and chi-square test were used to compare the related parameters in upright position, supine position and at 2 h after meals between two groups and within each group. Receiver oparative characteristic (ROC) curves of reflux parameters in upright position, supine position and 2 h after meals were drawn to determine the cut-off value, sensitivity and specificity in GERD diagnosis. Results:The proportion of patients with acid reflux in supine position of the control group was higher than that of the GERD group (41.0%, 25/61 vs. 8.50%, 17/200), and the difference was statistically significant ( χ2=36.53, P<0.01). In the control group, the acid reflux time in upright position, number of acid reflux, acid exposure time (AET), longest reflux time and number of weak acid reflux were more than those of in supine position in the same group (6.00 min(2.00 min, 13.50 min) vs. 0.00 min(0.00 min, 1.50 min), 16.00(8.00, 27.00) vs. 1.00(0.00, 3.00), 0.90%(0.33%, 1.88%) vs. 0.00%(0.00%, 0.30%), 2.00 min(1.00 min, 4.00 min) vs. 0.00 min(0.00 min, 1.00 min), 7.00(3.00, 11.00) vs. 1.00(0.00, 2.00), respectively) and the differences were statistically significant ( Z=5.43, 6.61, 5.06, 3.58 and 6.24, all P<0.01). In the GERD group, the acid reflux time, number of acid reflux, AET, longest reflux time and number of weak acid reflux in upright position were higher than those in supine position (51.00 min, (31.00 min, 86.75 min) vs. 8.00 min(1.00 min, 42.00 min), 60.00(48.00, 83.75) vs.6.00(2.00, 19.50), 7.30%(3.90%, 12.10%) vs. 1.50%(0.20%, 6.50%), 7.00 min(4.00, 12.00 min) vs. 4.00 min(1.00 min, 17.00 min), 1.00(0.00, 3.00) vs. 0.00(0.00, 2.00), 7.00(3.00, 12.00) vs. 0.00(0.00, 1.00), respectively) and the differences were statistically significant ( Z=7.92, 11.22, 6.90, 2.56, 5.11 and 11.76, all P<0.05). The acid reflux time, number of acid reflux, AET, longest reflux time and number of weak acid reflux at 2 h postprandial were 3.00 min(2.00 min, 9.00 min), 10.00(5.00, 18.00), 0.90%(0.40%, 1.98%), 1.00 min(0.00 min, 3.00 min), 4.00(1.50, 8.50)and 28.50 min(15.00 min, 54.75 min), 35.00(24.00, 52.00), 8.30%(4.32%, 15.83%), 6.00 min(3.00 min, 11.00 min), 4.00(2.00, 7.25), in the control and GERD groups, respectively, which were significantly higher than those in supine position in the same group ( Z=4.30, 6.33, 5.50, 3.40, 5.71 and 3.76, 9.21, 5.76, 1.97, 10.46, all P<0.05). Among 200 GERD patients, 125 patients had symptoms recorded during the 24 h esophageal pH combined impedance monitoring, the incidence of reflux symptoms in upright position was higher than that in supine position (89.6%, 112/125 vs. 65.6%, 82/125), and the difference was statistically significant ( χ2=20.71, P<0.01). The results of ROC curve analysis showed that the accuracy of acid reflux time in upright position in GERD prediction was the highest, with AUC value of 0.94 and cut-off value of 24.5 min, and the sensitivity and specificity in GERD diagnosis were 81.50% and 95.08%, respectively. The prediction accuracy of acid reflux times in upright position and AET in upright position for GERD was secondary, AUC value both were 0.93 and the cut-off value of the acid reflux number in upright position was 39.5, and the sensitivity and specificity in GERD diagnosis were 84.00% and 95.08%, respectively. The cut-off value of AET in upright position was 2.75%, the sensitivity and specificity in GERD diagnosis were 85.00% and 93.33%, respectively. The AUC value, cut-off value, sensitivity and specificity of AET at 2 h postprandial were 0.91, 4.60%, and 73.49% and 95.00%, respectively. Conclusions:Both GERD patients and non-GERD patients have more reflux in upright position, especially within 2 h after meals. The diagnostic values of acid reflux time in upright position, number of acid reflux, AET and AET 2 h after meals for GERD is high, and the AUC values are all >0.90, which can be used as a more comprehensive basis for the analysis and diagnosis of GERD.