title: Repeated versus single measurement of plasma omega-3 fatty acids and risk of heart failure.
abstract: OBJECTIVE
  Studies have previously examined the relation between a single measure of plasma fatty acids and risk of heart failure. However, it is unclear whether the use of repeated measures of fatty acids over time is required for the assessment of omega-3 fatty acids heart failure relation.
  
  
  METHODS
  Using a nested case-control design, this ancillary study used 421 cases and 421 matched controls from the Physicians' Health Study to assess the variability of plasma phospholipid fatty acids over time and compare the results of omega-3 fatty acids heart failure associations using a single versus repeated measurements of plasma phospholipid fatty acids. Plasma omega-3 fatty acids were measured at baseline (1982) and approximately 15 years later using gas chromatography.
  
  
  RESULTS
  Spearman's correlation coefficients between baseline and follow-up measures of α-linolenic acid (ALA), EPA, DPA, and DHA were 0.20, 0.45, 0.28, and 0.50, respectively, in the control series. Multivariable adjusted odds ratios for heart failure per standard deviation higher plasma ALA were 0.98 (95% CI 0.85-1.13) when using baseline ALA and 0.86 (95% CI 0.74-1.01) when using the average of baseline and follow-up ALA measurements. Corresponding odds ratios for total long chain omega-3 FAs (EPA + DHA + DPA) were 0.87 (0.73-1.03) and 0.88 (0.75-1.04).
  
  
  CONCLUSIONS
  Our data demonstrate modest correlation between measurements of plasma phospholipid fatty acids spaced by 15 years. A single measurement of plasma phospholipid fatty acids appears reasonable to estimate the risk of heart failure over long-term follow-up.
authors.affiliation: Division of Aging, Brigham and Women's Hospital, 1620 Tremont St. 3rd Floor, Boston, MA, 02120, USA, ldjousse@rics.bwh.harvard.edu.
authors.forename: Luc
authors.initials: L
authors.lastname: Djoussé
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Petrone
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Weir
authors.forename: Naomi Q
authors.initials: NQ
authors.lastname: Hanson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Glynn
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Tsai
authors.forename: J Michael
authors.initials: JM
authors.lastname: Gaziano
mesh_terms: D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D002849:Chromatography, Gas; D004281:Docosahexaenoic Acids / Q000097:blood*; D015118:Eicosapentaenoic Acid / Q000097:blood*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood; D011446:Prospective Studies; D012307:Risk Factors; D017962:alpha-Linolenic Acid / Q000097:blood*
chemical_list: D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; C026219:docosapentaenoic acid