title: Red blood cell polyunsaturated fatty acids and mortality in the Women's Health Initiative Memory Study.
abstract: The prognostic value of circulating polyunsaturated fatty acid (PUFA) levels is unclear.
  
  
  
  To determine the associations between red blood cell (RBC) PUFA levels and risk for death.
  
  
  
  This prospective cohort study included 6501 women aged 65 to 80 years who participated in the Women's Health Initiative Memory Study (enrolment began 1996). RBC PUFA levels were measured at baseline and expressed as a percent of total RBC PUFAs. PUFAs of primary interest were the n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their sum (the Omega-3 Index). PUFAs of secondary interest included the 2 major n-6 PUFAs, linoleic acid and arachidonic acid, and the PUFA factor score (a calculated variable including 6 PUFAs that accounts for their intercorrelations). The primary outcome was total mortality through August 2014.
  
  
  
  After a median of 14.9 years of follow-up, 1851 women (28.5%) had died. RBC levels of EPA and DHA were higher in the survivors (P < .002 for each). In the fully adjusted models, the hazard ratios (99% confidence intervals) for mortality associated with a 1 standard deviation PUFA increase for total mortality were 0.92 (0.85, 0.98) for the Omega-3 Index, 0.89 (0.82, 0.96) for EPA, 0.93 (0.87, 1.0) for DHA, and 0.76 (0.64, 0.90) for the PUFA factor score. There were no significant associations of alpha-linolenic acid, arachidonic acid or linoleic acid with total mortality.
  
  
  
  Higher RBC levels of marine n-3 PUFAs were associated with reduced risk for all-cause mortality. These findings support the beneficial relationship between the Omega-3 Index and health outcomes.
authors.affiliation: Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA; OmegaQuant Analytics, LLC, Sioux Falls, SD, USA. Electronic address: bill@omegaquant.com.
authors.forename: William S
authors.initials: WS
authors.lastname: Harris
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, IN, USA.
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, SD, USA.
authors.forename: James V
authors.initials: JV
authors.lastname: Pottala
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Espeland
authors.affiliation: HealthPartners Institute, Minneapolis, MN, USA.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Joann E
authors.initials: JE
authors.lastname: Manson
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.affiliation: Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA.
authors.forename: Theodore M
authors.initials: TM
authors.lastname: Brasky
authors.affiliation: Department of Epidemiology, College of Public Health and Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City, IA, USA.
authors.forename: Jennifer G
authors.initials: JG
authors.lastname: Robinson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004912:Erythrocytes / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D005260:Female; D006801:Humans; D009026:Mortality; D016387:Women's Health
chemical_list: D005231:Fatty Acids, Unsaturated
keywords: Docosahexaenoic acid; Eicosapentaenoic acid; Epidemiology; Omega-3 fatty acids; Omega-6 fatty acids; Prospective cohort study