Background: Objective measures of fatty acid intakes such as tissue levels of fatty acids more accurately reflect dietary intake compared to food frequency questionnaires. This study describes plasma fatty acid levels in New Zealanders with significant coronary artery disease and the relationship with mortality at 7.5 years.
Methods: This is prospective observational study. Fasting plasma samples were taken in in 420 consecutive patients with angiographic diagnosis of severe coronary disease requiring coronary artery bypass surgery. Plasma levels of fatty acids were measured by gas-chromatography mass-spectrometry. Mortality data was obtained by accessing details of the most recent contact with health professionals, review of clinical notes and the National Health Index database and death certificates.
Results: The mean age of participants was 68 (± 10) years and 83% were male. Saturated fats were 46.5 (± 1.2) %, unsaturated fats were 51.8 (± 1.3%) %, trans fatty acids 1.1 (± 0.69) % of total fats. Ruminant transfatty acids made up 67% of total plasma trans fatty acids. Saturated fats and ruminant trans fatty acids levels were not associated with increased total mortality (hazard ratio 0.93 (0.75 to 1.16) p=0.53 and.14 (0.85 to 1.53) p=0.39 respectively or cardiovascular mortality (hazard ratios 0.93 (0.75 to 1.16) p=0.53 and 0.91 (0.61 to 1.37, p=0.66).
Conclusion: Saturated and trans fatty acid levels in this population are higher than expected from food frequency questionnaires. More than two thirds of transfatty acids are from dairy food and meat. Neither saturated fats nor transfatty acids are associated with increased cardiovascular and total mortality.