In more recent years, cases have been separated into long segment Barrett’s esophagus (LSBE) and short segment Barrett’s esophagus (SSBE). The majority of cases reported have been SSBE with rates ranging from 0.04 to > 20%. More recent large

studies from Korea and Taiwan have yielded prevalence rates of 0.01 and 0.03 for LSBE and 0.14 and 2.4% for SSBE, respectively.55,57 The reporting of Barrett’s esophagus Akt inhibition has been hampered by the variability in diagnostic criteria used: presence of columnar epithelium only without histological examination, presence of intestinal metaplasia or specialized intestinal metaplasia on biopsies. SSBE is particularly difficult to ascertain in Asian patients with a higher prevalence of Helicobacter pylori infection and accompanying intestinal BVD-523 cell line metaplasia in the cardio-esophageal junction. It has been commented previously that Japanese studies report a higher prevalence of Barrett’s owing to a different definition of the cardio-esophageal junction.63 The Barrett’s data

from Asia are indeed confusing. What is apparent is the lower prevalence of LSBE compared to the West, and a low prevalence of Barrett’s-associated adenocarcinoma reported at the current time in the socio-economic history of the region.64 This may change in the future with a possible increase in adenocarcinoma, and close observations of the evolution of the disease are needed. The prevalence rates of both GERD symptoms and erosive esophagitis in the majority of recent reports have, in general, been higher than in earlier studies. This may be due to better diagnosis and recording of cases, but consistently higher rates from many centers in Asia is more likely to reflect a true increase in the prevalence of GERD. Time trend studies for both reflux symptoms and erosive esophagitis have been few

but have clearly shown an increasing trend in the prevalence of the disease. In a longitudinal 5 year follow-up study looking at reflux symptoms, Lim et al. from Singapore, reported a rise in the prevalence of reflux symptoms from 1.6% to 9.9%.34 However, only a small percentage of 上海皓元 the initial cohort of patients participated in the follow-up study. In another study from a small town in Western Japan over a 6-year period, 15.4% of GERD cases were identified as new cases.65 More studies on changes in prevalence of reflux esophagitis with time have been carried out. Ho et al. from Singapore tracked the prevalence of esophagitis in their endoscopy records over a 9-year period and recorded an increase from 3.9% to 9.8%.66 Similar reports have been published by Sollano et al. from the Philippines,67 Goh et al.68 from Malaysia, Lien et al.69 from Taiwan, and Kim et al. from Korea.70 All these studies have shown a highly significant increase in prevalence of erosive esophagitis over time. (Table 4). As with many other diseases, the increase in GERD in Asia is the result of the interaction between environmental factors and genetic predisposition.