Specialized intestinal metaplasia: analysis of prevalence, risk factors and association with gastro-oesophageal reflux disease
AIMS: There is an increasing awareness that short (less than 3 cm) segments of Barrett's epithelium and macroscopically normal cardia epithelium may harbour specialized intestinal metaplasia (SIM), a premalignant phenotype.  This was a prospective study of both the prevalence of SIM in an unselected population of patients attending for endoscopy, and the association of SIM with symptoms, lifestyle, medication, endoscopic oesophagitis and carditis.  METHODS: Two hundred consecutive patients underwent endoscopy.  Biopsies taken from just below the squamocolumnar junction were stained for SIM, and were analysed for carditis and Helicobacter pylori infection.  A detailed questionnaire of symptoms, tobacco consumption and the use of proton pump inhibitors was completed.  RESULTS: Forty-two patients (21 per cent) had SIM, 19 of 126 (15 per cent) in an endoscopically normal oesophagus, 15 of 63 (24 per cent) in a short segment of Barrett's epithelium and eight of 11 in classical Barrett's oesophagus.  Comparative analysis between the SIM positive and negative groups with respect to potential risk factors is outlined below.  Table 1.  CONCLUSION: SIM is prevalent in patients undergoing endoscopy, does not correlate with symptoms or with H. pylori infection, but is significantly associated with endoscopic and pathological markers of gastro-oesophageal reflux.