Acute coronary syndrome patients with depression have low blood cell membrane omega-3 fatty acid levels.
Level 4 - case-series / case-control
Cross-sectional observational study evaluating biomarker-symptom associations.
PubMed 18842751 · doi:10.1097/PSY.0b013e318188a01e
What was done
Researchers measured blood cell membrane fatty acid composition—specifically omega-3s (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and omega-6s (linoleic acid and arachidonic acid)—in 759 patients with confirmed acute coronary syndrome (ACS). Depressive symptoms were evaluated using the Patient Health Questionnaire-9 (PHQ). Multivariable linear regression was performed to evaluate the relationship between the omega-3 index (membrane EPA + DHA) and depressive symptoms while adjusting for demographic and clinical characteristics.
What was found
A significant inverse relationship was observed between the omega-3 index and PHQ depressive symptoms in the fully adjusted model (p = .034). Specifically, for every 4.54 percentage point increase in the omega-3 index, there was a 1-point decrease in depressive symptom score. Membrane levels of the omega-6 fatty acids linoleic acid and arachidonic acid did not differ between depressed and nondepressed ACS patients.
Why it matters
The study shows a biological link between low membrane omega-3 levels and depressive symptoms in post-ACS patients, highlighting a potential modifiable target linking mood disorders with cardiovascular disease.
Limits
The study is observational and cross-sectional, preventing any determination of causality or directionality. The observed clinical effect size is small (a 4.54% increase in the index corresponded to a single-point shift on the PHQ), and hard cardiovascular outcomes were not evaluated.
Cited by
- supports A lower omega-3 index is associated with an increased risk of depression.