Risk factors for colorrectal polyps in a Mexican population

The prevalence of colorectal polyps and adenomas in the general population of Mexico is unknown.

To determine the prevalence and risk factors for colorectal polyps detected during flexible sigmoidoscopy (FSIG) in asymptomatic patients.

From 1995 to 2008, FSIG was performed as part of a complete check-up in patients who had lived in northeast Mexico for over 5 years.

946 (794 males/152 females) were included in the study. The mean age was 48.8 years (range 21-91). A family history of colorectal cancer (FHCRC) was present in 2.2 % of the cases. The adenoma prevalence found in patients with a BMI < 25, 26-30 or > 30 was 7.3%, 6.2% and 10.2% respectively. Independent risk factor for colorrectal polyps and adenomas included a positive family history of colorrectal cancer (OR 12.4, 95% CI 19.1-230, and OR 12.4, 95% CI 4.1-37.3, respectively) and a body mass index < 25 (OR 4.2, 95% CI 4.2-14.2 and OR 4.2, 95% CI 1.8-9.7, respectively). Seventy two patients had polyps (7.6%) and 29 patients had adenomas (3%). The prevalence of polyps and adenomas on FSIG in patients younger than 50 years was 5.8% and 1.9% respectively, and among those older than 50 years, it was 8.9% and 4.8% respectively.

A positive family history of colorectal cancer and a body mass index < 25 are independent risk factors for colorectal polyps and adenomas. The adenoma prevalence found in our population was lower than the reported in developed countries.