title: Association of erythrocyte membrane fatty acids with changes in glycemia and risk of type 2 diabetes.
abstract: BACKGROUND
  The significance of erythrocyte membrane fatty acids (EMFAs) and their ratios to predict hyperglycemia and incident type 2 diabetes is unclear.
  
  
  OBJECTIVE
  We investigated EMFAs as predictors of the worsening of hyperglycemia and incident type 2 diabetes in a 5-y follow-up of a population-based study.
  
  
  METHODS
  We measured EMFAs in 1346 Finnish men aged 45-73 y at baseline [mean ± SD age: 55 ± 6 y; body mass index (in kg/m(2)): 26.5 ± 3.5]. Our prospective follow-up study included only men who were nondiabetic at baseline and who had data available at the 5-y follow-up visit (n = 735).
  
  
  RESULTS
  Our study showed that, after adjustment for confounding factors, palmitoleic acid (16:1n-7; P = 2.8 × 10(-7)), dihomo-γ-linolenic acid (20:3n-6; P = 2.3 × 10(-4)), the ratio of 16:1n-7 to 16:0 (P = 1.6 × 10(-8)) as a marker of stearoyl coenzyme A desaturase 1 activity, and the ratio of 20:3n-6 to 18:2n-6 (P = 9.4 × 10(-7)) as a marker of Δ(6)-desaturase activity significantly predicted the worsening of hyperglycemia (glucose area under the curve in an oral-glucose-tolerance test). In contrast, linoleic acid (18:2n-6; P = 0.0015) and the ratio of 18:1n-7 to 16:1n-7 (P = 1.5 × 10(-9)) as a marker of elongase activity had opposite associations. Statistical significance persisted even after adjustment for baseline insulin sensitivity, insulin secretion, and glycemia. Palmitoleic acid (P = 0.010) and the ratio of 16:1n-7 to 16:0 (P = 0.004) nominally predicted incident type 2 diabetes, whereas linoleic acid had an opposite association (P = 0.004), and n-3 polyunsaturated fatty acids did not show any associations.
  
  
  CONCLUSIONS
  EMFAs and their ratios are associated longitudinally with changes in glycemia and the risk type 2 diabetes.
authors.affiliation: Institute of Clinical Sciences, Internal Medicine (YM, HC, JV, AS, JK, and ML), the Institute of Biomedicine Physiology (JÅ), and the Institute of Public Health and Clinical Nutrition (MU and US), University of Eastern Finland, Kuopio, Finland, and the Research Unit (MU) and the Department of Medicine (HC, JK, and ML), Kuopio University Hospital, Kuopio, Finland.
authors.forename: Yuvaraj
authors.initials: Y
authors.lastname: Mahendran
authors.forename: Jyrki
authors.initials: J
authors.lastname: Ågren
authors.forename: Matti
authors.initials: M
authors.lastname: Uusitupa
authors.forename: Henna
authors.initials: H
authors.lastname: Cederberg
authors.forename: Jagadish
authors.initials: J
authors.lastname: Vangipurapu
authors.forename: Alena
authors.initials: A
authors.lastname: Stančáková
authors.forename: Ursula
authors.initials: U
authors.lastname: Schwab
authors.forename: Johanna
authors.initials: J
authors.lastname: Kuusisto
authors.forename: Markku
authors.initials: M
authors.lastname: Laakso
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000097:blood; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005227:Fatty Acids / Q000097:blood*; D005229:Fatty Acids, Monounsaturated / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000097:blood; D005387:Finland; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000150:complications; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D016014:Linear Models; D019787:Linoleic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism; D044465:White People
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D015525:Fatty Acids, Omega-3; D007328:Insulin; C008757:palmitoleic acid; D019787:Linoleic Acid; D013230:Stearoyl-CoA Desaturase; D015126:8,11,14-Eicosatrienoic Acid