title: Fatty acids measured in plasma and erythrocyte-membrane phospholipids and derived by food-frequency questionnaire and the risk of new-onset type 2 diabetes: a pilot study in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort.
abstract: BACKGROUND
  Epidemiologic evidence for the association between types of fatty acid and risk of type 2 diabetes is inconsistent. This may in part be due to the limitations of fatty acid measurement methods.
  
  
  OBJECTIVE
  The objective was to use 3 different measures of fatty acid to estimate the prospective association between fatty acid composition and development of incident diabetes.
  
  
  METHODS
  We analyzed 199 cases of clinically incident diabetes and 184 noncases aged 40-79 y at baseline in the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study. Fatty acids were derived from a food-frequency questionnaire (FFQ) and measured in plasma phospholipid (P-FA) and erythrocyte-membrane phospholipid (Ery-FA) fractions by gas chromatography.
  
  
  RESULTS
  There were stronger associations with diabetes risk with the use of objectively measured fatty acids (P-FA and Ery-FA) than with the FFQ in analyses adjusted for age, sex, and potential confounders. Positive associations with diabetes were greater in magnitude with the use of P-FA than with Ery-FA (highest:lowest tertiles): for example, the palmitic acid odds ratios (ORs) were 2.47 (95% CI: 1.37, 4.46) and 1.96 (95% CI: 1.10, 3.49), respectively. Inverse associations with diabetes were also stronger with the use of P-FA than with Ery-FA: for example, the OR for linoleic acid was 0.50 (95% CI: 0.28, 0.91) compared with 0.77 (95% CI: 0.43, 1.37), respectively.
  
  
  CONCLUSIONS
  The objective measurement of fatty acids with the use of either P-FA or Ery-FA identifies important associations with diabetes incidence that may be missed when assessed by FFQ. Fatty acids measured in P-FA appear to be more strongly associated with diabetes incidence. These findings endorse the use of objective measurement of fatty acids for nutritional-epidemiologic studies, and the apparently stronger findings for the plasma fraction should be confirmed in larger studies and in different populations.
authors.affiliation: Medical Research Council Epidemiology Unit, Cambridge, United Kingdom.
authors.forename: Pinal S
authors.initials: PS
authors.lastname: Patel
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Sharp
authors.forename: Eugene
authors.initials: E
authors.lastname: Jansen
authors.forename: Robert N
authors.initials: RN
authors.lastname: Luben
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wareham
authors.forename: Nita G
authors.initials: NG
authors.lastname: Forouhi
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000209:etiology*; D015930:Diet Records; D004041:Dietary Fats / Q000009:adverse effects*; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005227:Fatty Acids / Q000009:adverse effects / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood / Q000737:chemistry*; D010865:Pilot Projects; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D010743:Phospholipids