Plasma insulin, glucose, IGF-I, IGF-II, and IGFBP-3 and risk of recurrent colorectal adenomas.

Insulin and insulin-like growth factors (IGF's) are associated with an increased risk of colorectal adenomas. The association with recurrent adenomas is inadequately studied. We prospectively examined the relationship between insulin biomarkers and the risk of recurrent adenomas.Our analysis included 167 subjects with one or more adenomas detected on a baseline colonoscopy who had a surveillance colonoscopy within three to five years. We measured serum biomarkers in all subjects at baseline. ELISA was used to measure fasting plasma insulin, IGF-I, IGF-II, and IGF binding protein-3. The hexokinase assay was used to measure fasting plasma glucose by and immuno-turbidimetric assay to measure hemoglobin A1C.Subjects with recurrent adenomas were more likely to be male, overweight and have ≥3 adenomas at baseline. We found no significant associations between insulin (OR=1.6, 95% CI 0.7-3.5), glucose (OR=1.4, 95% CI 0.7-3.1), IGF-I (OR=0.7, 95% CI 0.3-1.5), IGF-II (OR=1.0, 95% CI 0.5-2.3), IGFBP-3 (OR=0.1, 95% CI 0.5-2.1), or anthropometric measures and recurrent adenomas.Our results do not support a role for insulin biomarkers and recurrent colorectal adenomas.