Efficacy of the Omega-3 Index in predicting non-alcoholic fatty liver disease in overweight and obese adults: a pilot study

Br J Nutr. 2015 Sep 14;114(5):780-7. doi: 10.1017/S0007114515002305. Epub 2015 Jul 23.

Abstract

Non-alcoholic fatty liver disease (NAFLD) is an independent predictor of CVD in otherwise healthy individuals. Low n-3 PUFA intake has been associated with the presence of NAFLD; however, the relationship between a biomarker of n-3 status - the Omega-3 Index - and liver fat is yet to be elucidated. A total of eighty overweight adults (fifty-six men) completed the anthropometric and biochemical measurements, including the Omega-3 Index, and underwent proton magnetic resonance spectroscopy assessment of liver fat. Bivariate correlations and multiple regression analyses were performed with reference to prediction of liver fat percentage. The mean Omega-3 Index was high in both NAFLD (intrahepatic lipid concentration≥5·5 %) and non-NAFLD groups. The Omega-3 Index, BMI, waist circumference, glucose, insulin, TAG, high-sensitive C-reactive protein (hsCRP) and alanine aminotransferase (ALT) were positively correlated, and HDL and erythrocyte n-6:n-3 ratio negatively correlated with liver fat concentration. Regression analysis found that simple anthropometric and demographic variables (waist, age) accounted for 31 % of the variance in liver fat and the addition of traditional cardiometabolic blood markers (TAG, HDL, hsCRP and ALT) increased the predictive power to 43 %. The addition of the novel erythrocyte fatty acid variable (Omega-3 Index) to the model only accounted for a further 3 % of the variance (P=0·049). In conclusion, the Omega-3 Index was associated with liver fat concentration but did not improve the overall capacity of demographic, anthropometric and blood markers to predict NAFLD.

Keywords: n-3 PUFA; 1H-MRS proton magnetic resonance spectroscopy; Biomarkers; IHL intrahepatic lipid; NAFLD non-alcoholic fatty liver disease; Non-alcoholic fatty liver; Omega-3 Index; hsCRP high-sensitive C-reactive protein.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / blood
  • Erythrocyte Membrane / metabolism*
  • Fatty Acids, Omega-3 / blood*
  • Female
  • Humans
  • Lipid Metabolism
  • Liver / metabolism*
  • Male
  • Middle Aged
  • Non-alcoholic Fatty Liver Disease / blood
  • Non-alcoholic Fatty Liver Disease / etiology
  • Non-alcoholic Fatty Liver Disease / metabolism*
  • Nutritional Status
  • Obesity / blood
  • Obesity / complications
  • Obesity / metabolism*
  • Pilot Projects
  • Young Adult

Substances

  • Biomarkers
  • Fatty Acids, Omega-3