Poster Presentation Australian & New Zealand Obesity Society 2014 Annual Scientific Meeting

Efficacy of the Omega-3 Index in predicting NAFLD in overweight and obese adults: a pilot study (#163)

Helen Parker 1 , Helen O'Connor 1 2 , Shelley Keating 1 , Jeffrey Cohn 3 , Manohar Garg 4 , Ian Caterson 5 , Jacob George 6 , Nathan Johnson 1 2
  1. Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
  2. Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
  3. Heart Research Institute, Newtown, NSW, Australia
  4. School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
  5. Boden Institute of Obesity Nutrition Exercise and Eating Disorders, University of Sydney, Sydney, NSW, Australia
  6. Storr Liver Unit, Westmead Millennium Institute, University of Sydney, Sydney, NSW, Australia

Background/Aims: Non-alcoholic fatty liver disease (NAFLD) is associated with overweight/obesity, and is an independent predictor of cardiovascular disease (CVD) in otherwise healthy individuals. Low intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) has been associated with NAFLD, however dietary reporting and analysis has many limitations. Therefore this study aimed to examine the relationship between a new biomarker of tissue n-3 (the Omega-3 Index) and liver fat, and to assess the predictive capacity of the Omega-3 Index for fatty liver.

Methods: Eighty overweight/obese non-smoker adults (56 males) underwent proton magnetic resonance spectroscopy (1H-MRS) and MRI to measure liver fat concentration and abdominal adiposity within seven days of undergoing blood analysis and anthropometry measurements. Correlations with liver fat were examined, and linear regression for the prediction of liver fat was performed. Mean±SEM are reported.

Results: Omega-3 Index was high in participants with and without NAFLD (9.0±0.3% and 8.4±0.3% respectively), and was positively correlated with liver fat (r=0.255, P=0.03). Linear regression analysis found that simple routine clinical measurements (BMI, waist circumference, age) together explained a third (33%) of the variance in liver fat, and the addition of common CVD blood markers (TG, HDL, hsCRP) increased the predictive power to 43%. However, addition of the novel Omega-3 Index, and red blood cell n-6/n-3 ratio to the model did not meaningfully or statistically improve the prediction of liver fat.

Conclusions: Against our hypothesis, the Omega-3 Index was positively correlated with liver fat. NAFLD is an important risk factor for CVD, and further research is needed to test the predictive capacity of the Omega-3 Index in higher risk populations. In healthy overweight/obese adults, simple routine clinical measurements are useful for predicting those at increased risk of NAFLD.

Funding source(s): Blackmores Ltd.; Diabetes Australia Research Trust.