Data adapted from: Allen KJ, Gurrin LC, Constantine CC, et. Al. Iron-Overload-Related Disease in HFE Hereditary Hemochromatosis. N Engl J Med 2008; 358:221-230 Iron Overload Status at time of Genotyping and at end of Follow-Up Sa1078 THE CHANGING EPIDEMIOLOGY OF GASTROESOPHAGEAL REFLUX DISEASE (GERD)- ARE WE SEEING YOUNGER PATIENTS? Takahisa Yamasaki, Colin Hemond, Ronnie Fass BACKGROUND GERD is a common global disease with increasing prevalence and conse- quently a greater burden on the health care system. Traditionally, GERD has been considered a disease of the middle aged and older subjects. As risk factors for GERD continue to affect a growing number of the adult population, concerns have been raised that increasingly younger subjects may develop GERD. AIMS To determine if GERD is increasingly becoming more prevalent in younger populations. METHODS A population based analysis of the Explorys dataset and Epic database of a safety net hospital was performed. Explorys is an aggregate electronic medical record database representing over 54 million patients. Prevalence of GERD as well as several variables such as age, gender, race and treatment with PPI were evaluated during an 11-year period. To ensure Explorys results reflect trends at a local level as well, similar data were obtained from Epic database of a community hospital. GERD patients were classified into 7 age groups (15-19, 20-29, 30-39, 40-49, 50-59, 60-69, >70 years-old). Patients younger than the age 15 were excluded from the analysis. Secular trends of GERD prevalence were assessed for each age group. RESULTS The prevalence of GERD increased in all age groups (15-19: 0.22%, 20-29: 2.37%, 30-39: 3.24%, 40-49: 2.79%, 50-59: 2.48%, 60-69: 0.75%) with the exception of those who were >70 years-old (-10.6%) in the Explorys dataset from 2006 to 2016. Similarly, the prevalence of GERD increased in all age groups (15-19: 0.02%, 20-29: 2.24%, 30-39: 4.48%, 40-49: 3.54%, 50-59: 3.21%) with the exception of those who were over 60 years-old in Epic (60-69 years-old: -0.51%, S-233 AGA Abstracts >70 years-old: -9.73%). The greatest rise in prevalence was seen in young adults aged 30- 39 years-old in both datasets. GERD was significantly more commune in those who were Caucasian and female. PPI usage fell substantially in those who were > 70 years-old in Explorys (-11.4%), in those who were over 60 years-old in Epic (60-69 years-old: -1.32%, >70 years-old: -11.6%). In contrast, PPI usage has significantly increased in the other age groups with the greatest rise in the 30-39 years-old group in both datasets (3.50% in Explorys, 4.57% in Epic). CONCLUSION GERD remains predominantly a disease of middle aged and older adults with higher prevalence among Caucasians and females. However, there is a significant increase in the prevalence of the younger age groups at the cost of older age groups. GERD is increasingly affecting younger patients. Sa1079 ARE THE RATES OF EOSINOPHILIC ESOPHAGITIS INCREASING IN KOREA? A STUDY BASED ON A DATABASE OF ENDOSCOPIES AT A SINGLE TERTIARY CARE CENTER Ga Hee Kim, Hwoon-Yong Jung, Kee Wook Jung, Young Soo Park, Jungbok Lee, Hee Kyong Na, Ji Yong Ahn, Jeong Hoon Lee, Do Hoon Kim, Kee Don Choi, Ho June Song, Gin Hyug Lee Background/Aims: The incidence and prevalence of eosinophilic esophagitis (EoE) have been increasing in Western countries. However, the exact epidemiology is still unclear in Asian countries, particularly in Korea. Thus, we investigated the diagnostic trends and clinical characteristics of EoE in Korea. Methods: We retrospectively reviewed a database of endoscopic procedures performed at a tertiary care center. From this review, we identified 25,271 reports of esophageal biopsies performed during upper endoscopies conducted between 2006 and 2017. The presence of more than 15 eosinophils per high-power field, in conjunction with symptoms related to esophageal dysfunction, were considered to indicate EoE. Results: A total of 74 patients (55 men, 19 women; mean age, 45.9 ± 14.3 years) were diagnosed with EoE. These patients' presenting symptoms included dysphagia (13.5%), epigastric pain (24.3%), heartburn (27.0%), and other symptoms (35.1%). The typical endoscopic appearance of EoE was noted in 68 patients (91.8%). Linear furrows were noted in 49 patients (66.2%), white exudates were seen in 34 patients (45.9%), and ringed esophagi were documented in 19 patients (25.6%). The mean eosinophilic count was 52.0 (±14.3) per high-power field. In an analysis using the Cochran-Armitage trend test, the rate of diagnosis of EoE was found to increase significantly between 2006 and 2017, from 0.29 diagnoses per 1000 esophageal biopsies to 7.99 diagnoses per 1000 esophageal biopsies (P for trend <0.001, Figure 1). Over the same time period, the esophageal biopsy rate did not increase, but actually decreased from 25.55/100,000 to 23.32/100,000. When patients were grouped seasonally, the number of EoE cases diagnosed during the summer months (n = 32) was found to be significantly higher compared with the number diagnosed in the fall and winter months (n = 13; P <0.001, Figure 2). The proportion of PPI-responsive esophageal eosinophilia in EoE patients was 31.6% (19/60). Conclusions: This is the first epidemiology study of increasing eosinophilic esophagitis in Asia. The number of patients with EoE increased significantly over the 12-year period investigated, regardless of the endoscopic esophageal biopsy rate. In Korea, a considerable proportion of patients with EoE had good prognoses, unlike patients in Western countries. Figure 1. EoE incidence and esophageal biopsy rates. AGA Abstracts