Iron intake and body iron stores as risk factors for Barrett's esophagus: a community-based study.

Abstract

High iron stores are a proposed modifiable risk factor for esophageal adenocarcinoma, but minimal human data exist. We evaluated whether iron intake and iron stores were associated with Barrett's esophagus, a metaplastic change that is a strong risk factor for esophageal adenocarcinoma. We conducted a case-control study within the Kaiser Permanente Northern California population. We identified all persons with a new diagnosis of Barrett's esophagus (cases); they were matched to persons with GERD (without Barrett's esophagus) and to population controls. Subjects completed examinations, dietary questionnaires, and testing for serum iron stores (ferritin and transferrin saturation). Analyses used unconditional logistic regression. We evaluated 319 cases, 312 GERD patients, and 313 population controls. Compared with population controls, Barrett's esophagus patients had lower dietary iron intakes (4th vs 1st quartiles, odds ratio [OR]= 0.37, 95% confidence interval [CI] 0.17-0.80), similar total iron intakes (including supplement use), and lower iron stores (4th vs 1st quartiles, ferritin OR = 0.24, 95% CI 0.14-0.40;% transferrin saturation OR = 0.66, 95% CI 0.41-1.04; P value trend <0.01 and 0.03, respectively). Similar associations were observed in comparisons with GERD controls and among subjects without clear sources of blood loss on endoscopy. Patients with Barrett's esophagus had lower dietary iron intakes and lower serum iron stores than controls in our population. These findings do not provide support for the current hypothesis that high iron stores or a high iron intake are risk factors for Barrett's esophagus, a potential early event in the carcinogenic sequence for esophageal adenocarcinoma.