Patients with chest pain at rest (unstable angina) or a heart attack (myocardial infarction) are usually diagnosed as having acute coronary syndrome (ACS). When patients with ACS also suffer from depression, they are more likely to die or experience recurrent cardiovascular events. Linking these two conditions may be a deficiency in essential fatty acids. In a new study, ACS patients with depression were found to have lower red blood cell membrane levels of omega-3 fatty acids, such as DHA (docosahexaenoic acid).
Researchers measured levels of different omega-3 and omega-6 fatty acids in the cell membranes of 759 patients diagnosed with ACS at 2 hospitals in Kansas City, Missouri. Clinical information was also collected from patient interviews and hospital charts. Levels of depressive symptoms were determined using the Patient Health Questionnaire-9 (PHQ), a nine-item depression screening tool that has been shown to be valid, sensitive, and specific for quantifying depressive symptoms.
Among the participants, 118 (15.5 percent) were found to have significant depressive symptoms. Those suffering from depression were more likely to be young, female, of a minority race, and have lower education levels. Compared with patients without depression, they were also more likely to be overweight and have higher rates of cardiovascular risk factors, including diabetes, high blood pressure, and smoking.
ACS patients with depression had lower levels of omega-3 fatty acids, particularly DHA, in their cell membranes. The researchers found an inverse relationship between depression and the omega-3 fatty acid index. For every 4.54 percent rise in this index, there was a one-point decline in depressive symptoms, as assessed by the PHQ. Membrane levels of eicosapentaenoic acid, another omega-3 fatty acid, were not lower in patients with ACS and depression.
The researchers indicate that interventions to raise the level of omega-3 fatty acids may help prevent both depression and adverse cardiovascular events. The study was supported in part by the Agency for Healthcare Research and Quality (HS11282).
See "Acute coronary syndrome patients with depression have low blood cell membrane omega-3 fatty acid levels," by Alpesh A. Amin, M.D., Rishi A. Menon, M.D., Kimberly J. Reid, M.S., and others, in the October 2008 Psychosomatic Medicine 70, pp. 856-862.