title: Association between serum fatty acids and lipoprotein subclass profile in healthy young adults: exploring common genetic and environmental factors.
abstract: OBJECTIVE
  Little is known about the associations of serum fatty acids with lipoprotein profile and the underlying genetic and environmental etiology of these relationships. We aimed to analyze the phenotypic association of serum n-6 and n-3 polyunsaturated (PUFAs), monounsaturated (MUFAs) and saturated (SFAs) fatty acids (relative proportion to total fatty acids) with lipids and lipoproteins, and to quantify common genetic and environmental factors determining their covariation.
  
  
  METHODS
  Two cohorts of healthy Finnish twins were assessed in young adulthood. Data were available for 1269 individual twins including 561 complete pairs. Serum metabolites were measured by nuclear magnetic resonance spectroscopy. Bivariate quantitative genetic models were used to decompose the phenotypic covariance between the pairs of traits into genetic and environmental components.
  
  
  RESULTS
  Among the strongest correlations observed, serum total n-6 PUFAs and linoleic acid were inversely (max. r=-0.65) and MUFAs positively (max. r=0.63) correlated with triglycerides and very low-density lipoprotein (VLDL) particle concentration, particularly with large VLDL (for n-6 PUFAs) and medium VLDL (for MUFAs). Genetic factors significantly contributed to their covariance with bivariate heritability estimates ranging from 44% to 56% for n-6 PUFAs and 58% to 66% for MUFAs. Genetic correlations with lipid traits were moderate to high (max. rA=-0.59 and 0.70 for n-6 PUFAs and MUFAs, respectively). Statistically significant, but substantially weaker phenotypic correlations of total n-3 PUFAs, docosahexaenoic acid (DHA) and SFAs with lipoprotein profile were not decomposed into their genetic and environmental components.
  
  
  CONCLUSIONS
  Shared genetic factors are important in explaining why higher concentrations of serum n-6 PUFAs and lower concentrations of serum MUFAs strongly associate with lower triglyceride and VLDL particle concentrations.
authors: Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country UPV/EHU, Leioa 48940, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain; Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki 00014, Finland. Electronic address: aline.jelenkovic@helsinki.fi.
authors: Aline
authors: A
authors: Jelenkovic
authors: Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki 00014, Finland.
authors: Leonie H
authors: LH
authors: Bogl
authors: Department of Psychological and Brain Sciences, Indiana University, Bloomington 47405, USA.
authors: Richard J
authors: RJ
authors: Rose
authors: Computational Medicine, Institute of Health Sciences, Faculty of Medicine, University of Oulu, 90014, Finland.
authors: Antti J
authors: AJ
authors: Kangas
authors: Computational Medicine, Institute of Health Sciences, Faculty of Medicine, University of Oulu, 90014, Finland; NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland, Kuopio 70211, Finland.
authors: Pasi
authors: P
authors: Soininen
authors: Computational Medicine, Institute of Health Sciences, Faculty of Medicine, University of Oulu, 90014, Finland; NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland, Kuopio 70211, Finland; Oulu University Hospital, Oulu, Finland; Computational Medicine, School of Social and Community Medicine and the Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK.
authors: Mika
authors: M
authors: Ala-Korpela
authors: Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki 00014, Finland; Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki 00271, Finland; Institute for Molecular Medicine FIMM, Helsinki 00014, Finland.
authors: Jaakko
authors: J
authors: Kaprio
authors: Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki 00014, Finland; Population Research Unit, Department of Social Research, University of Helsinki, Helsinki 00014, Finland.
authors: Karri
authors: K
authors: Silventoinen
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D004041:Dietary Fats; D005227:Fatty Acids / Q000097:blood*; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D059647:Gene-Environment Interaction; D058685:Genetic Pleiotropy; D006801:Humans; D008074:Lipoproteins / Q000097:blood* / Q000145:classification; D019906:Nuclear Magnetic Resonance, Biomolecular; D010316:Particle Size; D010641:Phenotype; D012016:Reference Values; D057566:Self Report; D011795:Surveys and Questionnaires; D014280:Triglycerides / Q000097:blood; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D008074:Lipoproteins; D014280:Triglycerides; D002784:Cholesterol
keywords: Environmental factors; Genetic pleiotropy; Lipoprotein profile; Serum fatty acids; Twins