Insulin, glucose, insulin resistance, and incident colorectal cancer in male smokers.

摘要: Background & Aims: Hyperinsulinemia is a putative colorectal cancer (CRC) risk factor. Insulin resistance (IR) commonly precedes hyperinsulinemia and can be quantitatively measured by using the homeostasis model assessment–insulin (HOMA-IR) index. To date, few studies have directly examined serum insulin as an indicator of CRC risk, none reported associations on basis HOMA-IR. Methods: We performed case-cohort study within Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study (n = 29,133). Baseline exposure fasting biomarker data were available for 134 incident case 399 non-case subjects. HOMA-IR was derived × glucose/22.5. Hazard ratios (HRs) 95% confidence intervals (CIs) estimated age-adjusted multivariable-adjusted Cox proportional hazards regression models. Results: Median (interquartile range) values insulin, glucose, 4.1 (2.9–7.2) mIU/L, 101 (94–108) mg/dL, 0.99 (0.69–1.98) subjects (2.7–6.1) 99 (93–107) 1.02 (0.69–1.53) subjects, respectively. On comparison highest versus lowest quartiles each biomarker, (HR, 1.84; CI, 1.03–3.30) 1.85; 1.06–3.24) significantly associated with CRC, whereas glucose marginally 1.70; 0.92–3.13) in However, trends across somewhat inconsistent ( P trend=.12, .04, .12, respectively), multivariable adjustment generally attenuated observed estimates. Conclusions: Data from this prospective male smokers provide limited support hyperinsulinemia, hyperglycemia, and/or factors.