Glycemic index and glycemic load are associated with breast cancer risk in rural and urban contexts: a multilevel analysis. Epidemiology Congress of the Americas 2016.

MUÑOZ SONIA; DÍAZ MARÍA DEL PILAR; TUMAS NATALIA; NICLIS CAMILA

Miami

Congreso; Epidemiology Congress of the Americas; 2016

Society for Epidemiologic Research

Introduction: The dietary glycemic index (GI) and glycemic load (GL) would increase the risk of diverse cancers, including breast cancer (BC). Factors other than individual exposures, such as contexts of residence, may be considered as determinants of this risk.Objectives: To evaluate the association of dietary GI and GL with the risk in BC occurrence of adult women, assessing the urban?rural context dependency in Córdoba province in 2008-2015 period.Material and Methods: A case-control study of BC was conducted. 323 cases and 527 controls -matched by age and residence- were interviewed with a validated food frequency questionnaire. The average daily GI for a subject?s diet was computed by summing the products of the GI value of each food times the amount of available carbohydrate (CH); then divided by the total amount of available CH consumed daily. The average GL was calculated by summing the products of the GI value of each food times the amount of available CH consumed daily divided by 100. Multilevel logistic regression models were estimated including GI or GL, age, BMI, energy and long chain fatty acids intake, age at menarche, number of children and age at first child as covariates at the individual level, and urbanization as a clustering factor (200,000 inhabitants), with the disease status being the response variable.Results: GI showed an increasing promoting effect for BC occurrence (OR: 1.43; 95%CI 1.04-1.99, tertile II vs. I and OR 1.55; 95%CI 1.26-1.91, tertile III vs. I). Instead, categories of GL showed no association with BC risk. A significant aggregation linked to the level of urbanization was observed, which explains above 15% of outcome variability, and improves the risk estimations.Conclusions: Our results suggest that a diet with high GI is associated with an increased risk of BC, with differences related to the urban-rural contexts of residence.