Height, predictors of C-peptide and cancer risk in men

Background Excessive energy intake tends to increase circulating levels of insulin and free insulin-like growth factor-1 (IGF-I), which may increase risk of some cancers that are common in Western countries. However, the relative importance of these hormonal factors during pre-adulthood and adulthood is unknown. Methods We prospectively examined height, as a marker of pre-adult IGF-I bioactivity, and modifiable adult determinants of insulin secretion, in relation to risk of cancer, particularly Western-related cancers (colon, pancreas, kidney, and aggressive prostate cancers) in 47 690 male health professionals. Information about dietary and lifestyle factors for these men was collected at baseline (1986) and was updated periodically. A C-peptide score, representing insulin secretion, was created by using body mass, physical activity, and diet in a stepwise linear regression to predict C-peptide level, in a sample of 263 cohort members.