Higher omega-3 index is associated with increased insulin sensitivity and more favourable metabolic profile in middle-aged overweight men

• Published in: Scientific reports 2014-10, Vol.4 (1), p.6697-6697, Article 6697
• Main Authors: Albert, Benjamin B., Derraik, José G. B., Brennan, Christine M., Biggs, Janene B., Smith, Greg C., Garg, Manohar L., Cameron-Smith, David, Hofman, Paul L., Cutfield, Wayne S.
• Format: Article
• Language: English
• Subjects: 692/308/409; 692/699/2743/2037; Adult; Blood Pressure; Body weight; Docosahexaenoic acid; Eicosapentaenoic acid; Erythrocytes; Fasting; Fatty acids; Fatty Acids, Omega-3 - genetics; Fatty Acids, Omega-3 - metabolism; Fish oils; Glucose tolerance; Glucose Tolerance Test; Humanities and Social Sciences; Humans; Insulin; Insulin Resistance - genetics; Laboratory testing; Male; Metabolism; Metabolome - genetics; Metabolomics; Middle age; Middle Aged; multidisciplinary; Overweight; Overweight - genetics; Overweight - metabolism; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep06697

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.