Prevalence and Risk Factors of Asymptomatic Colorectal Polyps in Taiwan

Purpose. To investigate the prevalence and risk factors of hyperplastic and adenomatous colorectal polyps in a Taiwanese general population. Methods. From January 2009 to December 2011, consecutive asymptomatic subjects undergoing a routine health check-up were evaluated by colonoscopy. The colorectal polyps were assessed, and medical history and demographic data were obtained from each patient. Logistic regression analysis was conducted to search the independent risk factors for asymptomatic hyperplastic and adenomatous colorectal polyps. Results. Of the 1899 asymptomatic subjects, the prevalences of hyperplastic polyps and adenomatous polyps were 11.1% and 16.1%, respectively. Multivariate analysis revealed that high body mass index (BMI > 25: OR, 1.32, 95% CI, 1.05-1.71) and current smoking (OR, 1.87, 95% CI, 1.42-2.71) were independent predictors for hyperplastic colorectal polyps. Age over 60 years old (OR, 3.49, 95% CI, 1.86-6.51), high body mass index (BMI > 25: OR, 1.75, 95% CI, 1.21-2.71), heavy alcohol consumption (OR, 2.01, 95% CI, 1.02-3.99), and current smoking (OR, 1.31, 95% CI, 1.04-1.58) were independent predictors for adenomatous colorectal polyps. Conclusion. High BMI and smoking are common risk factors for both adenomatous and hyperplastic polyps. Old age and alcohol consumption are additional risk factors for the development of adenomatous polyps.