Abdominal obesity and the risk of Barrett's esophagus

BACKGROUND: The association between overweight/obesity and the risk of Barrett's esophagus (BE) is unclear. Further, the association between body fat distribution and the risk of BE is unknown. METHODS: We conducted a retrospective case-control study in patients who underwent endoscopy at a single large VA Medical Center between 2000 and 2003. Cases were patients with documented BE who had an abdominal CT scan within 1 yr of the endoscopy, whereas controls were patients without BE (with or without erosive esophagitis) who also had an abdominal CT scan. The surface areas of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were calculated from CT scan images at level of intervertebral disc between L4 and L5, and body mass index (BMI) in kg/m(2) at the time of endoscopy was also recorded. Cases and controls were compared in univariate and multivariable analyses. RESULTS: We identified 36 cases and 93 controls. There were no significant differences between cases and controls in age (mean 63 yr), gender (98% men), or race (71% white Caucasian). BMI was significantly greater in cases than controls (27 vs 24; p= 0.006). BMI > 30 kg/m(2) was associated with a greater risk of BE than lower BMI (odds ratio 4.0; 95% CI: 1.4-11.1, p= 0.008). VAT was approximately 1.5-fold greater in cases than controls (183 vs 115 cm(2); p < 0.0001), whereas SAT was less different (248 vs 200 cm(2); p= 0.03). We estimated that each 10-cm(2) increase in VAT was associated with 9% increase in risk of BE. Interestingly, VAT remained independently associated with BE in the model that adjusted for BMI, and in that model, BMI was not significantly associated with BE. CONCLUSIONS: Obesity seems to be associated with an increased risk of BE. Abdominal visceral adiposity might mediate most of this risk.