Insights into insulin resistance, lifestyle, and anthropometric measures of patients with prior colorectal cancer compared to controls: A National Health and Nutrition Examination Survey (NHANES) Study.

Background: Insulin resistance (IR) increases the risk of index colorectal cancer (CRC) development. Limited data exist on IR values, lifestyle, and anthropometric alterations of patients after CRC diagnosis, a population at high risk for CRC recurrence.

Methods: This is a retrospective cohort study using the National Health and Nutrition Examination Survey (NHANES), 1999-2010. We identified patients with and without prior CRC above age 50. Our outcomes were lifestyle, anthropometric measures, and IR measured using the triglyceride to high-density lipoprotein ratio and the homeostasis model assessment IR.

Results: There were 146,841 patients with prior CRC and 26,979,507 without prior cancer (controls) in our cohort. Prior patients with CRC were significantly older than controls (75.8 vs 62.3, P < 0.01), however, there were no significant differences in gender, ethnicity, income, caloric intake, tobacco use or alcohol consumption between both groups. Multivariate analysis revealed no difference between prior patients with CRC and controls in triglyceride to high-density lipoprotein ratio (adjusted percentage change = -2.17; 95% CI: -27.96 to 18.43) or homeostasis model assessment IR (adjusted percentage change = -6.85; 95% CI: -35.74 to 15.90). Despite similar weight at age 25, prior CRC subjects had lower weights compared to controls (at time of NHANES survey, one and 10 years before survey and greatest weight). Furthermore prior CRC subjects gained less weight in the 10 years before survey.

Conclusion: Patients with prior CRC above age 50 have no conclusive evidence of increased IR compared to non-CRC controls. This is possibly due to lesser weight gain in the peri-CRC diagnosis or treatment period. Future efforts should focus on alternate etiologies for the increased CRC recurrence in this high-risk group.