title: Dietary glycemic load, glycemic index, and carbohydrate and risk of breast cancer in the Women's Health Initiative.
abstract: Dietary glycemic load (GL), glycemic index (GI), and carbohydrate could be associated with breast cancer risk by influencing long-term blood glucose and insulin concentrations. We examined associations between GL, GI, and carbohydrate and incident breast cancer in 148,767 Women's Heath Initiative (WHI) participants. Dietary variables were estimated from food frequency questionnaires administered at baseline. Self-reported breast cancers during follow-up were confirmed by medical records review. Cox proportional hazards regression modeled time to breast cancer within quintiles of GL, GI, and carbohydrate. There were 6,115 total breast cancers after a median follow-up of 8.0 yr. We observed no associations between GL, GI, or carbohydrate and total incident breast cancer, with hazard ratios and 95% confidence intervals for the highest vs. lowest quintiles of 1.08, 0.92-1.29 (P for trend = 0.27); 1.01, 0.91-1.12 (P = 0.74); and 0.95, 0.80-1.14 (P = 0.98), respectively. There was a trend toward significance for the positive association between GL and in situ cancers (1.40, 0.94-2.13; P = 0.07). Although there was no evidence of associations between GL, GI, or carbohydrate and total breast cancer risk in WHI participants, the suggestion of an association between GL and risk of in situ cancers requires further investigation.
authors.affiliation: Division of Preventive Medicine, Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham Alabama 35294, USA. jshikany@dopm.uab.edu
authors.forename: James M
authors.initials: JM
authors.lastname: Shikany
authors.forename: David T
authors.initials: DT
authors.lastname: Redden
authors.forename: Marian L
authors.initials: ML
authors.lastname: Neuhouser
authors.forename: Rowan T
authors.initials: RT
authors.lastname: Chlebowski
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rohan
authors.forename: Michael S
authors.initials: MS
authors.lastname: Simon
authors.forename: Simin
authors.initials: S
authors.lastname: Liu
authors.forename: Dorothy S
authors.initials: DS
authors.lastname: Lane
authors.forename: Lesley
authors.initials: L
authors.lastname: Tinker
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis*; D001943:Breast Neoplasms / Q000453:epidemiology*; D015331:Cohort Studies; D016001:Confidence Intervals; D004032:Diet; D004040:Dietary Carbohydrates / Q000032:analysis*; D002149:Energy Intake; D005260:Female; D005500:Follow-Up Studies; D038321:Glycemic Index; D006801:Humans; D007328:Insulin / Q000097:blood; D007407:Interviews as Topic; D008875:Middle Aged; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016387:Women's Health
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin