A Prospective Study of C-Peptide, Insulin-like Growth Factor-I, Insulin-like Growth Factor Binding Protein-1, and the Risk of Colorectal Cancer in Women

摘要: Hyperinsulinemia, hyperglycemia, and elevated insulin-like growth factor (IGF)-1 levels have been implicated in the etiology of colorectal cancer. However, joint effects insulin IGF-I not considered, whether hyperinsulinemia or hyperglycemia is more etiologically relevant unclear. IGF binding protein-1 (IGFBP-1) has hypothesized to mediate insulin, but epidemiologic data on IGFBP-1 are sparse. We conducted a nested case-control study among 32,826 women Nurses' Health Study who provided blood sample 1989 1990. After excluding diabetics, we confirmed 182 incident cancer cases over 10 years follow-up 350 controls. Cases were matched two controls year birth, date draw, fasting status. C-peptide weakly associated with risk colon [top quartile (Q4) versus bottom (Q1): multivariable relative (MVRR), 1.76; 95% confidence interval (95% CI), 0.85-3.63]. Fasting was inversely (MVRR, 0.28; CI, 0.11-0.75). observed no clear association between glycosylated hemoglobin for The IGFBP-3 molar ratio 2.82; 1.35-5.88), low both IGF-I/IGFBP-3 (or high IGFBP-1) at risk, elevation either sufficient increase risk. Although altering may be practical, growing burden obesity consequently hyperinsulinemia, which seems increasingly important cancer, target effective prevention.