Body mass index and the prevalence of high-risk colorectal adenomas in a population undergoing screening colonoscopy in Alberta, Canada.

Purpose: There is limited evidence regarding body mass index (BMI) as an early marker of high-risk adenoma (HRA) at the time of screening colonoscopy. Because high-risk adenomas (HRA) can develop into colorectal cancer (CRC), BMI could serve as an important clinical predictor of future risk of CRC.

Methods: We examined data from 1831 adults undergoing screening colonoscopy at the Forzani & MacPhail Colon Cancer Screening Center in Alberta, Canada. We fit multivariable logistic regression models to examine the association between BMI and HRA. Non-linear relationships for BMI on HRA were also evaluated using restricted cubic splines.

Results: The mean BMI in patients with HRA was 28.2 kg/m compared to 27.4 kg/m in patients without adenomas (t test: p = 0.003). In the adjusted models, those with a BMI over 30 kg/m had 1.45 (95% CI 1.05-2.00) times the odds of HRA detected during colonoscopy compared to those with a BMI below 25 kg/m. Examining BMI as continuous, the odds of HRA were 1.20 (95% CI 1.04-1.37) times higher for every 5 kg/m increase in BMI.

Conclusion: The findings of this study suggest that excess body mass is associated with higher risk of HRA among a screening population and may be useful an early marker of future disease.