Insulin resistance and impaired insulin secretion and gastrointestinal cancer risk in Korean adults: Preliminary results from Korean Genome and Epidemiology study.

Abstract

761 Background: To date, few studies conducted on the effect of insulin resistance or insulin secretory function on cancer risk in non-diabetic population. This study evaluated whether insulin resistance and/or insulin secretory function affect gastrointestinal cancer risk in the Korean population. Methods: We analyzed data from Korean Genome and Epidemiology Study, Korea Association Resource dataset. It consists of 10,030 participants aged 40-69y observed from 2001 to 2018. The risk of all cancers, and gastrointestinal cancers were assessed. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Homeostasis Model Assessment of Beta-cell function (HOMA-β) were used as indicators of insulin resistance and insulin secretory function. Results: In the final dataset, 8,649 individuals without previous history of any cancers were included. During an average follow-up of 15 years, 415 subjects (4.8%) developed cancers. Compared to the low HOMA-IR/high HOMA-β group (reference), diabetic patients had the highest risk of overall cancers, followed by high HOMA-IR/low HOMA-β group (Adjusted hazard ratio[95% confidence interval]: 1.74 [1.11 - 2.75] and 1.40 [0.96 – 2.06], respectively) Among gastrointestinal cancers, the risk of gastric cancer was higher in the low HOMA-IR/low HOMA-β and high HOMA-IR/high HOMA-β groups (1.92 [1.06 - 3.47] and 2.27 [1.26 - 4.06], respectively) When further analyzed by HOMA-β stratified by quartiles, the lowest quartile (Q1) showed an increased risk of gastric cancer compared to the highest-quartile (Q4; 1.84 [0.98 – 3.46], p = 0.06) In contrast, no significant results were observed regarding the colorectal cancer risk, when analyzed based on HOMA-IR and HOMA-β. However, when further analyzed by HOMA-IR stratified by quartiles, the highest quartile (Q4) exhibited a significantly elevated colorectal cancer risk compared to the lowest quartile (Q1; 2.14 [1.11 - 4.11], P for trend = 0.04). Conclusions: Insulin resistance and impaired insulin secretion function may increase the risk of cancer, but the underlying mechanisms may differ by cancer type.