Objective: The present study aimed to determine the association between body mass index [BMI] and colorectal adenoma in a Thai population participating in a colorectal cancer [CRC] screening project at Chulabhorn Hospital.

Materials and Methods: A total of 1,404 Thai individuals participated in the present study during July 2009. The participants were asked to complete questionnaires about their risk factors of
CRC. Body mass index was classified as follows: normal, <23; overweight, >23 to 24.9; obesity I, >25 to 29.9; and obesity II, >30 kg/m2. Multiple logistic regression analysis was used to identify the association between BMI and colorectal polyps.

Results: Colorectal adenoma was noted in 274 subjects (19.5%). An increase in BMI was associated with a higher risk for colorectal polyps compared with normal BMI as follows: overweight, odds
ratio [OR] 1.45 (95% confidence interval [CI] 1.04 to 2.03); obesity I, 1.58 (1.18 to 2.12); obesity II, 1.65 (1.09 to 2.48). However, the risk of occurrence of polyps in adenoma or advanced colorectal neoplasia was increased only among those with obesity: obesity I; OR 1.47 (95% CI 1.05 to 2.06), obesity II; 2.78 (1.18 to 6.75).

Conclusion: High BMI may increase the risk of development of colorectal adenoma, which may necessitate colonoscopy screening for colorectal cancer.

Keywords: Colorectal adenoma, Advanced colorectal neoplasia, Body mass index, Overweight, Obesity, Colorectal cancer screening