Abstract 8169: Relationship Between the Ratio of Serum Eicosapentaenoic Acid to Arachidonic Acid and the Risk of Death: the Hisayama Study

Abstract

Background: Recent evidence emerged to imply that greater intakes of omega-3 fatty acids reduce the risk of atherosclerotic disease. Some epidemiological studies suggested that a ratio of serum eicosapentaenoic acid to arachidonic acid (EPA/AA) is a possible good biomarker of risk for cardiovascular disease and death, but this issue has not been fully evaluated. We assessed the hypothesis that subjects with lower EPA/AA levels would be at increased risk of death from any causes and cardiovascular causes. Methods: We followed a total of 3,103 community-dwelling Japanese individuals aged 40 years or older, without history of cardiovascular disease, and with available EPA/AA data, for 5 years, and examined the relationship between EPA/AA levels and the risk of death from any and cardiovascular causes by using the Cox proportional hazards model. Results: The median value of EPA/AA levels in the study population was 0.41 (interquartile range, 0.29-0.59). During the follow-up, 191 subjects died in total, 48 of which were deceased from cardiovascular causes. The mortality rate from any causes increased gradually with lower EPA/AA levels: The risk of death from any causes increased significantly with EPA/AA levels of <0.25, 0.25-0.49, 0.5-0.74, and ≥0.75, being 23.5, 11.8, 12.8, and 11.5 per 1,000 person-years, respectively (p for trend =0.01). Likewise, there was an increasing trend in the mortality rate from cardiovascular causes with lower EPA/AA levels: 4.9, 4.0, 2.2, and 1.6 per 1,000 person-years for EPA/AA levels of <0.25, 0.25-0.49, 0.5-0.74, and ≥0.75, respectively (p for trend =0.03). After adjusting for potential confounding factors: namely, age, sex, hypertension, diabetes, total cholesterol, use of lipid-modifying agents, body mass index, smoking habits, and alcohol intake, subjects with EPA/AA level of <0.25 had a 2.04-fold (95% confidence interval [CI], 1.18-3.41) and 2.90-fold (95% CI, 0.78-10.77) greater risk of deaths from any causes and cardiovascular causes, as compared to those with EPA/AA level of ≥0.75. Conclusions: Our findings suggest that lower EPA/AA level is associated with a greater risk of death in the general Japanese population.