title: Higher omega-3 index is associated with increased insulin sensitivity and more favourable metabolic profile in middle-aged overweight men.
abstract: We assessed whether omega-3 index (red blood cell concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) was associated with insulin sensitivity and other metabolic outcomes in 47 overweight men aged 46.5 ± 5.1 years. Participants were assessed twice, 16 weeks apart. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Linear associations were examined; stratified analyses were carried out with participants separated according to the omega-3 index: lower tertiles (LOI; n = 31) and highest tertile (HOI; n = 16). Increasing omega-3 index was correlated with higher insulin sensitivity (r = 0.23; p = 0.025), higher disposition index (r = 0.20; p = 0.054), and lower CRP concentrations (r = -0.39; p < 0.0001). Insulin sensitivity was 43% higher in HOI than in LOI men (Matsuda index 6.83 vs 4.78; p = 0.009). Similarly, HOI men had disposition index that was 70% higher (p = 0.013) and fasting insulin concentrations 25% lower (p = 0.038). HOI men displayed lower nocturnal systolic blood pressure (-6.0 mmHg; p = 0.025) and greater systolic blood pressure dip (14.7 vs 10.8%; p = 0.039). Men in the HOI group also had lower concentrations of CRP (41% lower; p = 0.033) and free fatty acids (21% lower, p = 0.024). In conclusion, higher omega-3 index is associated with increased insulin sensitivity and a more favourable metabolic profile in middle-aged overweight men.
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Albert
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: José G B
authors.initials: JG
authors.lastname: Derraik
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Brennan
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Janene B
authors.initials: JB
authors.lastname: Biggs
authors.affiliation: Department of Pharmacology, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Greg C
authors.initials: GC
authors.lastname: Smith
authors.affiliation: Nutraceuticals Research Group, University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Manohar L
authors.initials: ML
authors.lastname: Garg
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: David
authors.initials: D
authors.lastname: Cameron-Smith
authors.affiliation: 1] Liggins Institute, University of Auckland, Auckland, New Zealand [2] Gravida: National Centre for Growth and Development, Auckland, New Zealand.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Hofman
authors.affiliation: 1] Liggins Institute, University of Auckland, Auckland, New Zealand [2] Gravida: National Centre for Growth and Development, Auckland, New Zealand.
authors.forename: Wayne S
authors.initials: WS
authors.lastname: Cutfield
mesh_terms: D000328:Adult; D001794:Blood Pressure; D015525:Fatty Acids, Omega-3 / Q000235:genetics* / Q000378:metabolism; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics*; D008297:Male; D055442:Metabolome / Q000235:genetics*; D055432:Metabolomics; D008875:Middle Aged; D050177:Overweight / Q000235:genetics* / Q000378:metabolism
chemical_list: D015525:Fatty Acids, Omega-3