Diabetes mellitus increases risk for colorectal adenomas in younger patients.

Aim: To determine if diabetes mellitus (DM) is associated with increased risk of colorectal adenomas in younger subjects.
Methods: This was a retrospective cohort study of 375 patients undergoing index colonoscopy at a single tertiary care center in the United States. Three cohorts of patients matched for exam date and gender were compared: (1) ages 40-49 years with DM; (2) ages 40-49 years without DM; and (3) ages 50-59 years without DM. Data collected included demographics, co-morbidities, colonoscopy and pathology results. Adenoma detection rates (ADR) were calculated and compared. Conditional logistic regression analysis was performed to determine the association between each cohort and ADR.
Results: One hundred and twenty-five patients ages 40-49 with DM met study eligibility criteria. Patients in the other two cohorts were randomly selected, matching for date of exam and gender. ADR was 14.4% in those ages 40-49 years without DM, 30.4% in those ages 40-49 years with DM, and 32.0% in those ages 50-59 years without DM. Compared to those ages 40-49 years without DM, ADR was higher in those ages 40-49 years with DM (OR = 3.1; 95%CI: 1.5-6.4; P = 0.002) and those ages 50-59 years without DM (OR = 2.9; 95%CI: 1.5-5.6; P = 0.002). There was no difference between the ADR in those ages 40-49 years with DM and those ages 50-59 years without DM (P = 0.83).
Conclusion: DM was associated with higher risk of colorectal adenomas in patients ages 40-49 years. These subjects harbored as many adenomas as those at the standard screening age of 50-59 years without DM.