Indicators of insulin resistance have been hypothesized to promote colorectal cancer.
Dr Andrew Flood and colleagues from Maryland, USA assayed fasting serum from 375 subjects with and 375 subjects without a recurrent adenoma during the course of the Polyp Prevention Trial.
The research team determined baseline concentrations of insulin and glucose, as well as changes in these measurements over the course of 4 years of follow-up evaluation.
|The association for glucose was most apparent for advanced adenomas|
The researchers estimated the relative risk of adenoma recurrence for each of these serum measures, odds ratios and 95% confidence intervals.
The team used multivariable logistic regression models adjusting for age, sex, body mass index, intervention group, and an interaction term for sex and intervention group.
For both insulin and glucose, there was a higher risk for subjects in the high quartile compared with the low quartile.
The association for glucose was most apparent for advanced adenomas, but for insulin, the team did not observe this pattern.
The research team then restricted the analysis to a subgroup without a family history of colorectal cancer.
The team observed an even stronger association between increased glucose at study entry and adenoma recurrence in the subgroup analysis.
Dr Flood's team concluded, "Our findings suggest that patients with increased insulin and glucose are at higher risk of adenoma recurrence."
"These patients are also at higher risk for those with increased glucose, the increase in risk for recurrence of advanced adenomas is even greater."