Background: Epidemiologic studies have suggested that the incidence of colorectal carcinoma may be related to overnutrition, but retrospective analysis of its relation to the body mass index (BMI: kg/m2) has produced conflicting data.
Methods: To avoid as many sources of statistical bias as possible, the relation between BMI and the presence of colorectal adenomas was investigated in a cross-sectional study.
Results: Two thousand twelve consecutive colonoscoped patients were investigated (532 patients with malignancies or other conditions associated with weight loss were excluded). The relation between BMI and observed colorectal adenomas was evaluated by a logistic model controlling for other prognostic factors such as age, sex, and serum cholesterol level. The subgroup of "high-risk" adenomas with an increased risk of malignant transformation was positively associated with the BMI in men of the age group 50.5-68.1 years (quintiles III and IV: odds ratio for the top quintile vs. the lowest quintile, 3.21; 95% confidence interval, 1.15-8.98).
Conclusions: It was concluded that the risk of developing high-risk adenomas tends to be increased in men who are overweight and that this association is independent of the positive association with the serum cholesterol level recently described.