Increase in Body Size Is Associated with an Increased Incidence of Advanced Adenomatous Colon Polyps in Male Veteran Patients

Background/Aims: Our aim was to determine how weight change influences the development of advanced adenomas. Methods: We performed a retrospective study of patients with adenomatous polyps (APs) on an index colonoscopy, and who also had a follow-up colonoscopy 3–5 years later. APs were evaluated for advanced features (i.e. size ≧1 cm in diameter and/or villous component and/or high-grade dysplasia). Patients were divided into 2 groups: those with no change or a reduction in their body mass index (BMI) during the interval between colonoscopies and those with an increase in BMI during the interval between colonoscopies. Results: 925 patients with a history of APs were identified. Univariate analysis showed that patients with an increase in BMI had more advanced APs (28 vs. 23%, p = 0.04), and a larger mean AP size (8.0 vs. 6.8 mm, p = 0.03) than those with a no change or decreased BMI. Multiple logistic regression analysis revealed that a decrease in BMI between colonoscopies was associated with a significantly reduced risk of developing advanced APs (OR: 0.4, 95% CI: 0.37–0.5, p < 0.05). Conclusions: An increase in weight in male veterans appears to be strongly associated with the development of clinically advanced AP lesions, even after adjustment for other known polyp risk factors.