Atrophic gastritis during long-term omeprazole therapy affects serum vitamin B-12 levels

Background: Omeprazole maintenance therapy for gastro-oesophageal reflux di sease (GERD) has been associated with an increased incidence of atrophic ga stritis in H. pylori-infected patients and with a decreased absorption of p rotein-bound. but not of unbound cobalamin. Aim: To test the hypothesis that the combination of decreased cobalamin abs orption and atrophic gastritis decreases serum cobalamin levels during omep razole therapy. Methods: Forty-nine H. pylori-positive GERD patients were treated with omep razole for a mean (+/- s.d.) period of 61 (25) months. At the start of omep razole treatment (T-0) and at the latest follow-up visit (T-1), serum was o btained for measurement of cobalamin. Corpus biopsy specimens were obtained at entry and follow-up for histopathological scoring according to the upda ted Sydney classification. Results: At inclusion, none of the 49 patients had signs of atrophic gastri tis. During follow-up, 15 patients (33%) developed atrophic gastritis, nine of whom had moderate to severe atrophy. These 15 patients did not differ f rom the other 34 patients with respect to age, serum cobalamin at To or the duration of follow-up. During follow-up, no change was observed in the med ian serum cobalamin level in the 34 patients without atrophy; (T-0) 312 (13 6-716) vs. (T-1) 341 (136-839) pmol/L (P = 0.1). In the 15 patients who dev eloped atrophy, a decrease in cobalamin was seen from 340 (171 to 787) at b aseline to 285 (156-716) at latest follow-up (P < 0.01). Conclusions: The development of atrophic gastritis during omeprazole treatm ent in H. pylori-positive GERD patients is associated with a decrease of se rum Vitamin B-12 levels.