Type 2 diabetes and the risk of colorectal polyps: A retrospective nationwide population-based study

The incidence rates of type 2 diabetes mellitus (T2DM) and colorectal polyps have been increasing over the last decades. However, direct associations between T2DM and colorectal polyps have not been extensively reported. We will explore the relationship between T2DM and colorectal polyps.In the retrospective study, we classified DM and NonDM groups (control) from 993,516 people in Taiwan nationwide population insurance database from the period of 2000 to 2013. We collected data on income and comorbidities through the international classification of diseases, ninth revision-clinical modification (ICD-9-CM) codes.The T2DM group had a higher incidence rate of colorectal polyps (31.97%, 95% confidence interval [CI] = 30.97-33.28) than the control group (25.9%, 95% CI = 25.1-26.72), and the crude incidence ratio was 1.235 (95% CI = 1.174-1.300). In 13 years of follow-up (2000-2013), T2DM was linked to a significantly higher cumulative probability of colorectal polyps (log-rank test: P = .0001).Patients with T2DM had a 1.23-fold higher risk of new colorectal polyps than control patients in 13 years of follow-up. We explain the T2DM increases incidence for colorectal polyps in long term follow-up.