Acute Coronary Syndrome Patients With Depression Have Low Blood Cell Membrane Omega-3 Fatty Acid Levels

Objective: To determine the extent to which levels of membrane eicosapentaenoic (EPA)+docosahexaenoic acids (DHA) (the omega-3 index) were associated with depression in patients with acute coronary syndrome (ACS). Depression is associated with worse cardiovascular (CV) outcomes in patients with ACS. Reduced levels of blood cell membrane omega-3 (n-3) fatty acids (FAs), an emerging risk factor for both CV disease and depression, may help to explain the link between depression and adverse CV outcomes. Methods: We measured membrane FA composition in 759 patients with confirmed ACS. The analysis included not only EPA and DHA but also the n-6 FAs linoleic and arachidonic acids (LA and AA). Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ). Multivariable linear regression was used to adjust for demographic and clinical characteristics. Results: There was a significant inverse relationship between the n-3 index and depressive symptoms (PHQ) in the fully adjusted model (p = .034). For every 4.54% point rise in the n-3 index, there was a 1-point decline in depressive symptoms. In contrast to the n-3 FAs, membrane levels of the n-6 FAs LA and AA were not different between depressed and nondepressed ACS patients. Conclusion: We found an inverse relationship between the n-3 index and the prevalence of depressive symptoms in patients with ACS. Therefore, this study supports the hypothesis that reduced n-3 FA tissue levels are a common and potentially modifiable link between depression and adverse CV outcomes. AA = arachidonic acid; ACS = acute coronary syndrome; BMI = body mass index; CAD = coronary artery disease; CV = cardiovascular; DHA = docosahexaenoic acid; EPA = eicosapentanenoic acid; FA = fatty acids; GC = gas chromatography; MI = myocardial infarction; n-3 = omega-3; n-6 = omega-6; PHQ = Patient Health Questionnaire-9; UA = unstable angina.