Age-Specific Differences in the Risk of Colorectal Precursor Lesions Among Patients with Type 2 Diabetes Undergoing Surveillance Colonoscopy

Document Type : Research Articles


1 Department of Haematology and Oncology, The Queen Elizabeth Hospital, Woodville South, South Australia, 5011, Australia.

2 SAHMRI Colorectal Node, Basil Hetzel Institute, Woodville South, South Australia 5011, Australia.

3 Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, 5000, Australia.

4 Biology Department, College of Science, University of Duhok, Duhok, Kurdistan, Iraq.

5 Adelaide Health Technology Assessment (AHTA), School of Public Health, The University of Adelaide, Adelaide, South Australia, 5000, Australia.

6 Bowel Health Service, Flinders Medical Centre, Bedford Park, South Australia, 5042, Australia.

7 Cancer Research, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia, 5042, Australia.


Background: The incidence rate of colorectal cancer (CRC) in young adults is rising in parallel with type 2 diabetes (T2D). The majority of CRC develop through two main subtypes of precursor lesions; adenomas and serrated lesions. The associations between age and T2D on development of precursor lesions remain uncertain. Objectives: We studied the association of T2D with the development of adenomas and serrated lesions in individuals <50 versus ≥50 years of age, in a population undergoing long-term regular surveillance colonoscopy due to an elevated risk of CRC. Methods: A case-control study was conducted on patients who were enrolled in a surveillance colonoscopy program between 2010-2020. Findings at colonoscopy, clinical and demographic features were collected. Adjusted and unadjusted binary logistic regression assessed the association of age, T2D, sex, and other medical conditions and lifestyle-related factors with different subtypes of precursor lesions diagnosed at colonoscopy. Cox proportional hazards model analysis determined the association of T2D and other confounders with development time for precursor lesions. Results: Cases included 412 patients <50y [mean age 38.7 (range, 24-49y)] and 824 sex-matched controls ≥50y [62.1 (50-75y)]. Individuals <50y were less likely to have been diagnosed with T2D than those ≥50y (7% vs 22%, P-value<0.001). During the follow-up period, there was no significant association between T2D and diagnosis of any precursor lesions, but when considering development time, individuals with T2D developed non-significant adenomas earlier than those without T2D (HR =1.46; 95% CI: 1.14–1.87; P-value=0.003). However, this was not independent of age or findings at index colonoscopy. Conclusions: T2D does not further increase the incidence of adenomas or serrated lesions in either a young or older cohort undergoing long-term surveillance colonoscopy.


Main Subjects