Polyunsaturated fatty acids (PUFAs) levels in patients with cardiovascular diseases (CVDs) with and without depression

Background: Cardiovascular diseases (CVDs) are commonly comorbid with depression and vice versa. Polyunsaturated fatty acids (PUFAs) have been suggested to mediate in CVDs and depression in cross-sectional and observational studies. With the patients of CVDs, we investigated the role of depression on the effect of PUFAs. Methods: Forty-four patients with CVDs were recruited and assessed with Hamilton depression rating scale (HAMD). Patients' CVDs markers were measured by electrocardiogram and their red blood cell (RBC) samples were collected for PUFAs analyses. Results: The data of 44 subjects were analyzed; where 10 participants (23%) with CVDs had moderate or severe depression, defined by a HAMD score more than 19 points. The moderate depression group had lower docosahexaenoic acid (DHA), omega-3 (N3) and omega-6(N6) to N3 (N6/N3) ratio than non-depression group (HAMD score less than 8), while no differences between the 2 groups in terms of corrected QT (QTc) intervals and high sensitivity C-reactive protein (hsCRP) levels. Furthermore, when we analyzed the data with an inclusion of a more heterogeneous depression group, where HAMD score is greater than or equal to 10 (mild depression group, N = 24), the differences in PUFAs levels between the 2 groups disappear. Secondary analysis of the moderate depression group showed a positive correlation between DHA, N3 PUFAs, and N6/N3 ratio and total HAMD scores, a positive correlation between N3 PUFAs and QTc intervals in non-depression group. Conclusion: Moderate depression group of patients with CVDs had lower levels of DHA, N3, and N6/N3 ratio than non-depression group, while both groups had no differences in QTc and hsCRP. On the other hand, the differences in PUFAs levels disappear in the mild depression group after inclusion of patients with CVDs with greater heterogeneity of depression. Hence, the role of N3 PUFAs is implicated in depression of patients with CVDs if the depression status is more strictly defined.