Serum C‐peptide is positively associated with the presence of colorectal adenomas (136.7)

Abstract

Activation of the insulin ‐‐ insulin‐like growth factor (IGF) signaling axis is hypothesized to increase colon cancer risk. The aim of this study was to determine if serum factors related to insulin or insulin signaling were associated with advanced colon polyps in males. 126 men (48 ‐ 65 yr) were recruited at time of colonoscopy, and blood was collected. Odds ratios were determined using logistic regression for polyp number and polytomous logistic regression for polyp severity. 29% of the men in our study had a tubular adenoma. Participants with C‐peptide levels above 3.3ng/ml were 3.8 (CI: 1.3 ‐ 11.1) times more likely than those with C‐peptide levels less than 1.8ng/ml to have a tubular adenoma. For each category increase in C‐peptide, an individual was 2.0 (CI: 1.2 ‐ 3.4) times more likely to have a tubular adenoma than no polyp. Those individuals with serum soluble receptor for advanced glycation end products (sRAGE) greater than 120.4pg/ml were 0.3 (CI: 0.1 ‐ 0.9) times less likely than those with sRAGE lower than 94.5pg/ml to have 蠅3 polyps than no polyps. For each category increase in sRAGE, an individual was 0.5 (CI: 0.3 ‐ 0.9) times less likely to have 蠅3 polyps than no polyps. Other factors, such as insulin growth factor binding proteins, were not associated with polyp presence or severity in this population. Serum C‐peptide levels are a potential biomarker of polyp severity in white males. Grant Funding Source: Supported by NCI 1R03CA142000 and MSU CTSI