Published online Apr 16, 2021. doi: 10.12998/wjcc.v9.i11.2433
Peer-review started: December 5, 2020
First decision: December 17, 2020
Revised: December 23, 2020
Accepted: February 25, 2021
Article in press: February 25, 2021
Published online: April 16, 2021
Multiple factors, including both social determinants of health (e.g., access to quality healthcare) and biological gene-environment factors that may promote oncogenic transformation, have been implicated in the persistently increased colorectal cancer (CRC) incidence and mortality in Black/African Ancestry (AA) individuals compared with those of all other races in the United States.
We explored how these multiple factors affect the risk of adenoma, a precursor stage for CRC, during index colonoscopies performed at two hospitals located 50 miles apart that serve two very disparate populations. While type 2 diabetes (T2DM) has been associated with increased adenoma detection in predominantly White/European Ancestry (EA), one of the few studies conducted on a predominantly Black/AA population detected no significant effect of T2DM on adenoma risk in Black/AA women.
To measure the univariate effect of T2DM on the adenoma detection rate (ADR) in a predominantly Black/AA population, recent hemoglobin A1c (HbA1c) levels were used to further stratify the nondiabetic patients into prediabetic patients (pre-DM) and controls with normal glycemic status (control). To conduct a multivariable analysis of the effect of race and diabetes status in the combined datasets collected on a predominantly underinsured Black/AA population and a predominantly insured White/EA population while controlling for multiple factors.
The datasets were assembled by manual curation of endoscopy and clinical records in the electronic medical record at each hospital using the same vocabulary. Multivariable analysis utilized generalized linear mixed models, which incorporated both fixed effects (age, sex, race, diabetes status, obesity, smoking status, aspirin use and insurance status) and random effects (institution and individual colonoscopists).
The ADR was significantly higher in the T2DM group than in the control group in the predominantly underinsured Black/AA population, but no significant difference in the ADR was detected for the pre-DM group compared to both the T2DM group and the control group. T2DM along with age, obesity, smoking status, and male sex were significantly associated with a higher ADR after combining the datasets for the two disparate populations. Race, insurance status and aspirin use were not significant.
These results indicate that T2DM increases adenoma risk in both Black/AA and White/EA individuals.
We plan to conduct a prospective study recruiting patients scheduled for index screening colonoscopies at both institutions to measure HbA1c and fasting blood glucose preprocedure. We plan to refer individuals with abnormal levels for the management of prediabetes and diabetes.