Type 2 Diabetes and the Risk of Colorectal Adenomas: Black Women's Health Study

Abstract

Evidence for the association of type 2 diabetes mellitus (DM) with colorectal neoplasms is contradictory, and African Americans have been underrepresented in the studies published to date. In a nested case-control study (1995-2009), we examined DM and insulin therapy as risk factors for colorectal adenomas in African American women enrolled in the ongoing Black Women's Health Study. From women reporting ever having undergone a gastrointestinal endoscopy, 917 cases of colorectal adenoma were compared with 2,751 controls without a colorectal polyp, matched on age and follow-up time. Cases were verified by medical record review. We used multivariable logistic regression analyses that included DM exposures and selected confounders. There were no overall associations between DM and adenoma risk or between insulin use and adenoma risk. However, DM without insulin use was inversely associated with risk of colon adenomas (odds ratio (OR) = 0.71, 95% confidence interval (CI): 0.52, 0.97) but not rectal adenomas. DM was inversely associated with adenoma risk in women older than 55 years (OR = 0.64, 95% CI: 0.44, 0.91) but not in women 55 years or younger (OR = 1.24, 95% CI: 0.81, 1.89). Future research should attempt to replicate the unexpected inverse association of DM with colon adenoma risk among older African American women.

Type 2 diabetes mellitus and risk of colorectal adenoma: a meta-analysis of observational studies

“…Of those remaining articles, we excluded studies that : (1) reported the data of adenoma recurrence were excluded [ 31 , 32 ], (2) did not reported the RRs of getting CRA separately but mixed CRC and CRA patients [ 31 ], and (3) discussed the relationship between metformin [ 33 ] or insulin use [ 34 ] and CRA. We identified 17 studies that met all of our criteria [ 13 – 20 , 35 – 44 ], including four conference abstracts [ 36 , 37 , 43 , 44 ]. Figure 1 provides a flow chart of study selection.…”

“…However, the association between T2DM and the risk of CRA risk has not yet been fully established. Some researchers asserted that there were no overall associations between T2DM and CRA risk [ 13 – 16 ], while others reported a higher risk [ 17 – 20 ]. To further examine these findings and provide evidence of association between T2DM and risk of CRA risk, we performed a meta-analysis about T2DM on the risk of CRA.…”

Different effects of metformin and insulin on primary and secondary chemoprevention of colorectal adenoma in diabetes type 2: Traditional and Bayesian meta-analysis

“…1) (References in Table 1: Kim et al, 2015[ 22 ]; Kanadiya et al, 2013[ 20 ]; Cho et al, 2014[ 6 ]; Jain et al, 2016[ 18 ]; Eddi et al, 2012[ 12 ]; Lewis et al, 2007[ 26 ]; Chung et al, 2008[ 7 ]; Lee et al, 2012[ 25 ]; Marks et al, 2015[ 29 ]; Han et al, 2017[ 16 ]; Shin et al, 2013[ 32 ]) and 2 (Tab. 2) (References in Table 2: Chung et al, 2008[ 7 ]; Jain et al, 2016[ 18 ]; Eddi et al, 2012[ 12 ]; Dash et al, 2013[ 9 ]; Wong et al, 2012[ 39 ]). Of the 11 studies presented based on metformin treatment (Table 1 (Tab.…”

“…The summary ORs of meta-analysis (OR=1.43, 95 % CI=1.15 to 1.78; P=0.002) revealed that there was a significant positive association between colorectal adenoma incidence and insulin intake between T2DM patients according to the 5 including studies (Figure 5 (Fig. 5) ; References in Figure 5: Chung et al, 2008[ 7 ]; Dash et al, 2013[ 9 ]; Jain et al, 2016[ 18 ]; Wong et al, 2012[ 39 ]; Eddi et al, 2012[ 12 ]). Then the insulin recipient patients had a risk of colorectal adenoma compared with those who did not.…”

Diabetes-induced mechanophysiological changes in the small intestine and colon

“…Large prospective studies have demonstrated that DM is associated with an increased risk of colon cancer in people investigated[211-217]. Many meta-analysis studies also support a correlation between DM and increased risk of colon cancer[142-144,218-222].…”