Oral Bisphosphonates and the Risk of Barrett's Esophagus: Case-Control Analysis of US Veterans
Objectives: This study examined Barrett's esophagus (BE) risk factors in veterans to determine the association between risk of BE and use of oral bisphosphonates. Methods: We conducted a case-control study among eligible patients scheduled for an elective esophagogastroduodenoscopy (EGD) and a sample of patients eligible for screening colonoscopy recruited from primary care clinics from a single VA Medical Center. Cases with definitive BE were compared with controls; all underwent study EGD. Use of oral bisphosphonates was ascertained by reviewing filled prescriptions in electronic pharmacy records. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs), using multivariate logistic regression modeling while adjusting for sex, age, race, proton-pump inhibitor use, hiatal hernia, waist-to-hip ratio, Helicobacter pylori infection, and gastroesophageal reflux disorder (GERD) symptoms. Results: There were 285 BE cases, 1,122 endoscopy controls, and 496 primary care controls. Alendronate and risedronate were the only oral bisphosphonates prescribed. The proportion of BE cases with filled prescription of oral bisphosphonates (4.6%) was greater than in endoscopy controls (1.6%) or primary care controls (2.9%). In the adjusted analysis, oral bisphosphonate use was significantly associated with BE risk (OR=2.33; 95% CI: 1.11-4.88) compared with the combined control groups. This association remained significant when BE cases were compared with endoscopy controls only (OR=2.74; 95% CI: 1.28-5.87) but was attenuated when compared with primary care controls only (OR=2.60; 95% CI: 0.99-6.84). The association was observed in patients with GERD symptoms (OR=3.29; 95% CI: 1.36-7.97) but not in those without GERD symptoms. Conclusion: Oral bisphosphonate use may increase the risk for BE, especially among patients with GERD.