788 VARIABLE GEOGRAPHICAL DIFFERENCES OF AMBULATORY ESOPHAGEAL REFLUX MONITORING IN MEXICO

Abstract

Abstract Ambulatory esophageal reflux monitoring (AEpH) is useful in evaluating persistent or refractory esophageal symptoms despite adequate pharmacologic and/or surgical therapy. There is limited information whether there are geographical or regional differences in the diagnostic outcome of this test. Aim Characterize the diagnostic outcome of AEpH in a diverse population of Mexico. Analyze whether there is regional geographical diagnostic variability. Methods Data was collected from four major referral centers representing diverse geographical areas of Mexico: Mexico City-Central (two centers, years 2016-2020), Veracruz-South (years 2015-2020) and Monterrey-North (years 2013-2020). Consecutive patients undergoing AEpH with persistent GERD symptoms despite PPI therapy and negative upper endoscopy (no erosive disease >C or D LA classification) were entered into a data base and analyzed. Patients were classified as: NERD (acid exposure time (AET > 6.0%); hypersensitive esophagus (normal AET and positive symptom index (SI) or positive symptom association probability [SAP]); functional heartburn (NL AET, neg SI/SAP). Statistics: ANOVA, Chi-square and descriptive methods were used to compare variables among groups. Results 969 cases met inclusion criteria: 311 (32.1%) Central, 430 (44.3%) South, and 228 (23.5%) North. The results are summarized in the table. There were more women 618(63.8%) than men 351(36.2%); p < 0.001 with a mean age 47.7 ± 14.3. Patients were older in Central-Mexico 49.3 ± 13.6 years vs South 47.5 ± 15 and North 46.1 ± 13.6; p = 0.033. Functional heartburn was the most common diagnosis overall and more prevalent in Central-Mexico 171(55%) vs North 97(42.5%) and South 160(37.2%); p < 0.001. NERD was more predominant in the South 171(39.8%) vs North 72(31.6%) and Central-Mexico 98(31.5%); p = 0.029. Hypersensitive esophagus was more frequent in the North 59(25.9%) vs South 99(23%), and Central 42(13.5%); p < 0.001. Conclusion This is the first large data base study to evaluate the outcome of ambulatory esophageal reflux pH testing in Mexico. Our findings indicate a geographical variability of GERD phenotypes and suggest that further investigations are warranted to determine the causes of this distribution.