title: Red Blood Cell Fatty Acids and Incident Diabetes Mellitus in the Women's Health Initiative Memory Study.
abstract: BACKGROUND
  The relations between dietary and/or circulating levels of fatty acids and the development of type 2 diabetes is unclear. Protective associations with the marine omega-3 fatty acids and linoleic acid, and with a marker of fatty acid desaturase activity delta-5 desaturase (D5D ratio) have been reported, as have adverse relations with saturated fatty acids and D6D ratio.
  
  
  OBJECTIVE
  To determine the associations between red blood cell (RBC) fatty acid distributions and incident type 2 diabetes.
  
  
  METHODS
  Prospective observational cohort study nested in the Women's Health Initiative Memory Study.
  
  
  METHODS
  General population.
  
  
  METHODS
  Postmenopausal women.
  
  
  METHODS
  Self-reported incident type 2 diabetes.
  
  
  RESULTS
  There were 703 new cases of type 2 diabetes over 11 years of follow up among 6379 postmenopausal women. In the fully adjusted models, baseline RBC D5D ratio was inversely associated with incident type 2 diabetes [Hazard Ratio (HR) 0.88, 95% confidence interval (CI) 0.81-0.95) per 1 SD increase. Similarly, baseline RBC D6D ratio and palmitic acid were directly associated with incident type 2 diabetes (HR 1.14, 95% CI 1.04-1.25; and HR 1.24, 95% CI 1.14-1.35, respectively). None of these relations were materially altered by excluding incident cases in the first two years of follow-up. There were no significant relations with eicosapentaenoic, docosahexaenoic or linoleic acids.
  
  
  CONCLUSIONS
  Whether altered fatty acid desaturase activities or palmitic acid levels are causally related to the development of type 2 diabetes cannot be determined from this study, but our findings suggest that proportions of certain fatty acids in RBC membranes are associated with risk for type 2 diabetes.
authors.affiliation: Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, and OmegaQuant Analytics, LLC, Sioux Falls, South Dakota, United States of America.
authors.forename: William S
authors.initials: WS
authors.lastname: Harris
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, Indiana, United States of America.
authors.forename: Juhua
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota, United States of America.
authors.forename: James V
authors.initials: JV
authors.lastname: Pottala
authors.affiliation: HealthPartners Foundation for Education and Research, Minneapolis, Minnesota, United States of America.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Espeland
authors.affiliation: Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America.
authors.forename: Jennifer G
authors.initials: JG
authors.lastname: Robinson
mesh_terms: D000368:Aged; D000090943:Delta-5 Fatty Acid Desaturase; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology / Q000473:pathology; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism*; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D005260:Female; D006801:Humans; D015994:Incidence; D019787:Linoleic Acid / Q000378:metabolism*; D050602:Linoleoyl-CoA Desaturase / Q000378:metabolism*; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood; D016016:Proportional Hazards Models; D011446:Prospective Studies; D014481:United States / Q000453:epidemiology; D016387:Women's Health
chemical_list: D000090943:Delta-5 Fatty Acid Desaturase; D015525:Fatty Acids, Omega-3; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase