Research Papers: Breast CancerGlycemic index, glycemic load and invasive breast cancer incidence in postmenopausal women: The PREDIMED studyCastro-Quezada, Itandehuia; Sánchez-Villegas, Almudenaa,b; Martínez-González, Miguel Á.b,d; Salas-Salvadó, Jordib,f; Corella, Doloresb,g; Estruch, Ramónb,h; Schröder, Helmutc,i; Álvarez-Pérez, Jacquelinea,b; Ruiz-López, María D.m,n; Artacho, Reyesm; Ros, Emiliob,j; Bulló, Mónicab,f; Sorli, Jose V.b,g; Fitó, Montserratb,i; Ruiz-Gutiérrez, Valentinab,o; Toledo, Estefaníab,d; Buil-Cosiales, Pilarb,e; García Rodríguez, Antoniob,q; Lapetra, Joséb,p; Pintó, Xavierb,k; Salaverría, Itziarb; Tur, Josep A.b,r; Romaguera, Dorab,s; Tresserra-Rimbau, Annab,l; Serra-Majem, Lluísa,b; PREDIMED Study InvestigatorsAuthor Information aResearch Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria bThe PREDIMED Prevention with Mediterranean Diet Research Network (RD 06/0045) and CIBER Physiopathology of Obesity and Nutrition (CIBEROBN, CB06/03) cCIBER Epidemiology and Public Health (CIBERESP), Spanish Government, Madrid dDepartment of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Navarra eNavarra’s Health Service-Osasunbidea, Pamplona fHuman Nutrition Department, School of Medicine, University Rovira i Virgili, Tarragona gDepartment of Preventive Medicine, School of Medicine, University of Valencia, Valencia hDepartment of Internal Medicine, Hospital Clinic, August Pi i Sunyer Biomedical Research Institute (IDIBAPS) iCardiovascular Risk and Nutrition Research Group (CARIN-ULEC), Hospital del Mar Medical Research Institute (IMIM) jLipid Clinic, Endocrinology and Nutrition Service, Hospital Clinic, August Pi i Sunyer Biomedical Research Institute (IDIBAPS) kInternal Medicine Service, Hospital of Bellvitge lDepartment of Nutrition and Bromatology, School of Pharmacy, University of Barcelona, Barcelona mDepartment of Nutrition and Food Science, School of Pharmacy, Campus Universitario de la Cartuja nInstitute of Nutrition and Food Technologies, Granada oGroup of Nutrition and Lipid Metabolism, Instituto de la Grasa (CSIC) pDepartment of Family Medicine, Primary Care Division of Sevilla, San Pablo Health Center, Sevilla qDepartment of Preventive Medicine, School of Medicine, University of Malaga, Malaga rLaboratory of Physical Activity Sciences, Community Nutrition and Oxidative Stress Research Group (IUNICS), University of the Balearic Islands sHealth Research Institute of Palma (IdISPa), Son Espases University Hospital, Mallorca, Spain Correspondence to Lluís Serra-Majem, MD, PhD, Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe “Físico” s/n, 35016, Las Palmas de Gran Canaria, Spain Tel: +34 928 453477; fax: +34 928 453475; e-mail: [email protected] European Journal of Cancer Prevention: November 2016 - Volume 25 - Issue 6 - p 524-532 doi: 10.1097/CEJ.0000000000000209 Buy Metrics Abstract The objective of this study was to evaluate the prospective associations between dietary glycemic index (GI) and glycemic load (GL) and the risk for invasive breast cancer incidence in postmenopausal women at high cardiovascular disease (CVD) risk. This study was conducted within the framework of the PREvención con DIeta MEDiterránea (PREDIMED) study, a nutritional intervention trial for primary cardiovascular prevention. We included 4010 women aged between 60 and 80 years who were initially free from breast cancer but at high risk for CVD disease. Dietary information was collected using a validated 137-item food frequency questionnaire. We assigned GI values using the International Tables of GI and GL values. Cases were ascertained through yearly consultation of medical records and through consultation of the National Death Index. Only cases confirmed by results from cytology tests or histological evaluation were included. We estimated multivariable-adjusted hazard ratios for invasive breast cancer risk across tertiles of energy-adjusted dietary GI/GL using Cox regression models. We repeated our analyses using yearly repeated measures of GI/GL intakes. No associations were found between baseline dietary GI/GL and invasive breast cancer incidence. The multivariable hazard ratio and 95% confidence interval (CI) for the top tertile of dietary GI was 1.02 (95% CI: 0.42–2.46) and for dietary GL was 1.00 (95% CI: 0.44–2.30) when compared with the bottom tertile. Repeated-measures analyses yielded similar results. In sensitivity analyses, no significant associations were observed for women with obesity or diabetes. Dietary GI and GL did not appear to be associated with an increased risk for invasive breast cancer in postmenopausal women at high CVD risk. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.