We investigated the relationships between the ratio of serum n-3 polyunsaturated fatty acids (n-3PUFAs: eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) to n-6PUFA (arachidonic acid [AA]) and the prevalence of coronary artery disease (CAD), and assessed the association of the ratio of serum n-3 to n-6 PUFAs with atherosclerosis-related markers.
This study was designed as a hospital-based cross-sectional study of 649 consecutive outpatients who had undergone regular examinations between April 2009 and October 2009. We divided the patients into 5 groups based on the quintiles of the EPA/AA ratio or quintiles of the DHA/AA ratio to determine independent factors for the prevalence of CAD.
In multivariate logistic regression analyses after adjustment for coronary risk factors and serum n-3PUFAs levels to minimize confounding factors to the extent possible because the serum levels of EPA and DHA showed a strong correlation (r = 0.812, P < 0.0001), the group with the highest EPA/AA ratio had a lower probability of CAD prevalence (odds ratio: 0.328, 95% confidence interval: 0.113 to 0.956, P = 0.041), but this was not true for the DHA/AA ratio. Multivariate analysis showed an increase in the EPA/AA ratio, but not in the DHA/AA ratio, was associated with effects on atherosclerosis-related markers, especially triglyceride-rich lipoproteins, high-density lipoprotein cholesterol (HDL-C) containing apolipoprotein A-1, and leukocyte count in an anti-atherogenic direction.
The results suggest a higher EPA/AA ratio, but not a higher DHA/AA ratio, might be associated with a lower prevalence of CAD and improvements of triglyceride metabolism and HDL metabolism, and systemic inflammation.