title: Fatty acid profile of plasma NEFA does not reflect adipose tissue fatty acid profile.
abstract: Adipose tissue (AT) fatty acid (FA) composition partly reflects habitual dietary intake. Circulating NEFA are mobilised from AT and might act as a minimally invasive surrogate marker of AT FA profile. Agreement between twenty-eight FA in AT and plasma NEFA was assessed using concordance coefficients in 204 male and female participants in a 12-month intervention using supplements to increase the intake of EPA and DHA. Concordance coefficients generally showed very poor agreement between AT FA and plasma NEFA at baseline SFA: 0·07; MUFA: 0·03; n-6 PUFA: 0·28; n-3 PUFA: 0·01). Participants were randomly divided into training (70 %) and validation (30 %) data sets, and models to predict AT and dietary FA were fitted using data from the training set, and their predictive ability was assessed using data from the validation set. AT n-6 PUFA and SFA were predicted from plasma NEFA with moderate accuracy (mean absolute percentage error n-6 PUFA: 11 % and SFA: 8 %), but predicted values were unable to distinguish between low, medium and high FA values, with only 25 % of n-6 PUFA and 33 % of SFA predicted values correctly assigned to the appropriate tertile group. Despite an association between AT and plasma NEFA EPA (P=0·001) and DHA (P=0·01) at baseline, there was no association after the intervention. To conclude, plasma NEFA are not a suitable surrogate for AT FA.
authors.affiliation: 1MRC Human Nutrition Research,Elsie Widdowson Laboratory,Cambridge CB1 9NL,UK.
authors.forename: Celia G
authors.initials: CG
authors.lastname: Walker
authors.affiliation: 1MRC Human Nutrition Research,Elsie Widdowson Laboratory,Cambridge CB1 9NL,UK.
authors.forename: Lucy M
authors.initials: LM
authors.lastname: Browning
authors.affiliation: 2MRC Biostatistics Unit Hub for Trials Methodology Research,Institute of Public Health,University Forvie Site,Cambridge CB2 0SR,UK.
authors.forename: Lynne
authors.initials: L
authors.lastname: Stecher
authors.affiliation: 4Human Development & Health Academic Unit, Faculty of Medicine,University of Southampton,Southampton General Hospital,Southampton SO16 6YD,UK.
authors.forename: Annette L
authors.initials: AL
authors.lastname: West
authors.affiliation: 4Human Development & Health Academic Unit, Faculty of Medicine,University of Southampton,Southampton General Hospital,Southampton SO16 6YD,UK.
authors.forename: Jackie
authors.initials: J
authors.lastname: Madden
authors.affiliation: 1MRC Human Nutrition Research,Elsie Widdowson Laboratory,Cambridge CB1 9NL,UK.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Jebb
authors.affiliation: 4Human Development & Health Academic Unit, Faculty of Medicine,University of Southampton,Southampton General Hospital,Southampton SO16 6YD,UK.
authors.forename: Philip C
authors.initials: PC
authors.lastname: Calder
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000097:blood / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood* / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000097:blood / Q000378:metabolism; D005260:Female; D005395:Fish Oils / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status
chemical_list: D015415:Biomarkers; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D005230:Fatty Acids, Nonesterified; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005395:Fish Oils; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid
keywords: AT adipose tissue; Adipose tissue fatty acids; DHA supplementation; EHA supplementation; FA fatty acids; NEFA; Prediction equations; Surrogate markers