Dietary insulin index and insulin load in relation to endometrial cancer risk in the Nurses' Health Study
A partir des données de la cohorte "Nurses' Health Study", cette étude évalue l'association entre la charge glycémique, l'index insulinique des aliments et le risque de cancer de l'endomètre
Background: While unopposed estrogen exposure is considered the main driver of endometrial carcinogenesis, factors associated with states of insulin resistance and hyperinsulinemia are independently associated with endometrial cancer risk. We used dietary insulin load and insulin index scores to represent the estimated insulin demand of overall diets and assessed their association with endometrial cancer risk in the prospective Nurses' Health Study. Methods: We estimated incidence rate ratios (RRs) and 95% confidence intervals (CI) for risk of invasive endometrial cancer using Cox proportional hazards models. Between the baseline dietary questionnaire (1980) and 2010, we identified a total of 798 incident invasive epithelial endometrial adenocarcinomas over 1,417,167 person-years of follow-up. Results: Dietary insulin scores were not associated with overall risk of endometrial cancer. Comparing women in the highest to the lowest quintile, the multivariable-adjusted RRs of endometrial cancer were 1.07 (95% CI: 0.84, 1.35) for cumulative average dietary insulin load and 1.03 (95% CI: 0.82, 1.31) for cumulative average dietary insulin index. Findings did not vary substantially by alcohol consumption, total dietary fiber intake, or BMI and/or physical activity (Pheterogeneity ≥ 0.10). Conclusions: Intake of a diet predicted to stimulate a high postprandial insulin response was not associated with endometrial cancer risk in this large prospective study. Considering the complex interplay of diet, lifestyle and genetic factors contributing to the hyperinsulinemic state, dietary measures alone may not sufficiently capture absolute long-term insulin exposure. Impact: This study is the first to investigate dietary insulin scores in relation to endometrial cancer risk.