title: Long-term risk of type 2 diabetes in relation to habitual iron intake in women with a history of gestational diabetes: a prospective cohort study.
abstract: BACKGROUND
  An iron overload may induce pancreatic islet damage and increase risk of diabetes. Women with a history of gestational diabetes mellitus (GDM) are at high risk of developing type 2 diabetes mellitus (T2DM) after pregnancy.
  
  
  OBJECTIVE
  We aimed to examine the association of habitual iron intake with long-term risk of T2DM in this high-risk population.
  
  
  METHODS
  We included 3976 women with a history of GDM from the Nurses' Health Study II cohort as part of the ongoing Diabetes & Women's Health Study. The women were followed up through 2009. Iron intake was assessed with the use of a validated food-frequency questionnaire in 1991 and every 4 y thereafter. We used Cox proportional hazards models to estimate HRs and 95% CIs.
  
  
  RESULTS
  We documented 641 incident T2DM cases during 57,683 person-years of observation. Adjusted HRs for T2DM for the highest quartile compared with the lowest quartile were 1.64 (95% CI: 1.20, 2.25; P-trend = 0.02) for total iron intake and 1.80 (95% CI: 1.18, 2.74; P-trend = 0.005) for dietary heme iron intake. In addition, women who consumed ≥30.0 mg supplemental Fe/d, compared with nonusers, had an adjusted HR of 1.83 (95% CI: 1.25, 2.70; P-trend = 0.002).
  
  
  CONCLUSIONS
  In women with a history of GDM, greater intakes of total iron, dietary heme iron, and supplemental iron were associated with higher risk of T2DM.
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Rockville, MD;
authors.forename: Wei
authors.initials: W
authors.lastname: Bao
authors.affiliation: Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, MA; Channing Division of Network Medicine, Department of Medicine, and.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Chavarro
authors.affiliation: Epidemiology, Harvard School of Public Health, Boston, MA; Division of Preventive Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; and.
authors.forename: Deirdre K
authors.initials: DK
authors.lastname: Tobias
authors.affiliation: Division of Biostatistics and Epidemiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.
authors.forename: Katherine
authors.initials: K
authors.lastname: Bowers
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Rockville, MD;
authors.forename: Shanshan
authors.initials: S
authors.lastname: Li
authors.affiliation: Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, MA; Channing Division of Network Medicine, Department of Medicine, and.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Rockville, MD; zhangcu@mail.nih.gov.
authors.forename: Cuilin
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology*; D016640:Diabetes, Gestational / Q000503:physiopathology*; D019587:Dietary Supplements / Q000009:adverse effects*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006418:Heme / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D019190:Iron Overload / Q000209:etiology / Q000503:physiopathology*; D019266:Iron, Dietary / Q000009:adverse effects* / Q000506:poisoning; D008460:Meat / Q000009:adverse effects*; D009726:Nurses; D009749:Nutrition Surveys; D011247:Pregnancy; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D019266:Iron, Dietary; D006418:Heme
keywords: diet; gestational diabetes mellitus; heme iron; iron; type 2 diabetes mellitus