title: Fatty acids derived from a food frequency questionnaire and measured in the erythrocyte membrane in relation to adiponectin and leptin concentrations.
abstract: OBJECTIVE
  Evidence on the association between fatty acids and adiponectin and leptin concentrations is scarce and inconsistent, which may in part be due to limitations of dietary reporting methods. We aimed to estimate the association of fatty acids, derived from a food frequency questionnaire (FFQ) and measured in the erythrocyte membrane, with adiponectin and leptin concentrations.
  
  
  METHODS
  We studied 330 non-institutionalized inhabitants of Porto (52.4% women; age range: 26-64 years) evaluated in 2010-2011, as part of the EPIPorto cohort study. Fatty acids were derived from a validated semiquantitative FFQ and measured in the erythrocyte membrane by gas chromatography. Serum concentrations of adiponectin and leptin were determined through radioimmunoassay. Regression coefficients (β) and 95% confidence intervals (95% CI) were obtained from linear regression models, after controlling for gender, age, education, leisure time physical activity and total body fat percentage (obtained from dual energy X-ray absorptiometry).
  
  
  RESULTS
  Fatty acids measured by FFQ showed no significant associations with both adipokines. Lauric and linoleic acids, measured in the erythrocyte membrane, were significantly and positively associated with adiponectin (β=0.292, 95% CI: 0.168-0.416; β=0.150, 95% CI: 0.020-0.280) and leptin (β=0.071, 95% CI: 0.003-0.138; β=0.071, 95% CI: 0.002-0.140), whereas total n-3, eicosapentaenoic and docosahexaenoic acids were significantly but negatively associated with adiponectin (β=-0.289, 95% CI: -0.420 to -0.159; β=-0.174, 95% CI -0.307 to -0.040; β=-0.253, 95% CI -0.383 to -0.124) and leptin (β=-0.151, 95% CI: -0.220 to -0.083; β=-0.080, 95% CI: -0.151 to -0.009; β=-0.146, 95% CI: -0.214 to -0.078). Positive significant associations of palmitic and trans-fatty acids with adiponectin were also observed.
  
  
  CONCLUSIONS
  A positive association of lauric and linoleic acids and a negative association of total n-3 fatty acids with both adipokines were observed only with fatty acids measured in the erythrocyte membrane.
authors.affiliation: Institute of Public Health, University of Porto, Porto, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Santos
authors.affiliation: 1] Institute of Public Health, University of Porto, Porto, Portugal [2] Department of Clinical Epidemiology, Predictive Medicine and Public Health and Cardiovascular Research and Development Unit, University of Porto Medical School, Porto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Oliveira
authors.affiliation: REQUIMTE, Laboratory of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, Porto, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Pinho
authors.affiliation: 1] Institute of Public Health, University of Porto, Porto, Portugal [2] REQUIMTE, Laboratory of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, Porto, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Casal
authors.affiliation: 1] Institute of Public Health, University of Porto, Porto, Portugal [2] Department of Clinical Epidemiology, Predictive Medicine and Public Health and Cardiovascular Research and Development Unit, University of Porto Medical School, Porto, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Lopes
mesh_terms: D015502:Absorptiometry, Photon; D052242:Adiponectin / Q000097:blood*; D000328:Adult; D003430:Cross-Sectional Studies; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005227:Fatty Acids / Q000008:administration & dosage / Q000097:blood*; D005260:Female; D006801:Humans; D007850:Lauric Acids / Q000008:administration & dosage / Q000097:blood; D020738:Leptin / Q000097:blood*; D016014:Linear Models; D019787:Linoleic Acid / Q000008:administration & dosage / Q000097:blood; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011446:Prospective Studies; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D044242:Trans Fatty Acids / Q000008:administration & dosage / Q000097:blood; D014280:Triglycerides / Q000097:blood
chemical_list: D052242:Adiponectin; D004041:Dietary Fats; D005227:Fatty Acids; D007850:Lauric Acids; D020738:Leptin; D044242:Trans Fatty Acids; D014280:Triglycerides; C030358:lauric acid; D004281:Docosahexaenoic Acids; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid