An association between colonic adenoma and abdominal obesity: a cross-sectional study

BACKGROUND Colorectal adenoma is a precursor lesion of colorectal cancer and thus, it is an important target for preventing colorectal cancer. Only a few studies suggest an association between colorectal adenoma and obesity, but results show considerable heterogeneity. In this study, we investigated the association between colorectal adenoma and waist circumference. METHODS 165 adenoma cases and 365 polyp-free controls with a normal colon were compared in this cross-sectional study. Subjects underwent screening colonoscopy by experienced endoscopists. Demographic data, including smoking habit, were obtained by interview and waist circumference and anthropometric measurements were examined. Dietary intakes were evaluated using a food frequency questionnaire, and abdominal obesity was evaluated by measuring waist circumference. Statistical analysis was performed using SPSS for 13.0. RESULTS Age, waist circumference, and BMI were significantly higher in cases than controls. And smokers and men were more prevalent among cases than controls.Among the abdominal obese subjects, 45.6% had 1 or more adenoma, and 9.0% of these had advanced adenoma, whereas among subjects with a normal waist circumference, only 25.7% had 1 or more adenomas. The prevalence of adenoma was higher among abdominal obese group (P < 0.05). Logistic regression analysis showed that abdominal obesity was associated with an increased risk of colorectal adenoma (OR, 2.74; 95% CI, 1.66~4.51 in men, OR, 2.58; 95% CI, 1.08~6.12 in women). These associations persisted even after adjusting for BMI. While BMI was found to be weekly associated with the risk of adenoma among men at the highest BMI levels. However, BMI was not associated with the risk for adenoma after adjusting for waist circumference. CONCLUSION Our data suggest that abdominal obesity is associated with an increased risk of colorectal adenoma.