Assessment of Irisin Levels in Patients With Bipolar Depression and Unipolar Depression

Abstract

Aim: Irisin is a myokine and adipokine which has neural effects such as playing a role in neural proliferation. There are studies in the literature reporting that irisin could be associated with neurodegenerative processes. Therefore, in this study, we aimed to evaluate the irisin levels in patients with bipolar depression and major depressive disorder. Materials and Methods: Thirty patients with bipolar disorder (BD) depressive episodes, 28 patients with major depressive disorder (MDD) and 30 healthy controls (HCs) were included in the study. Sociodemographic and clinical data were collected from each participant. Serum irisin levels were determined by enzyme-linked immunosorbent assay (ELISA) kits, and the severity of the depression was measured by the Hamilton Depression Rating Scale. Results: There was no statistically significant difference between patients with MDD, bipolar disorder depressive episodes and healthy controls in terms of irisin levels. The statistical analysis revealed significant negative correlations between levels of irisin and duration of illness (r=-0.500, p<0.01) in MDD. Irisin serum level was found to be negatively correlated with the number of depressive episodes (r=-0.620, p<0.01) in patients with MDD. Discussion: Irisin's role in the development of depression in patients with coronary artery diseases and patients having strokes has been studied previously in the literature. Our study is the first that evaluated levels of irisin in patients with bipolar depression and major depressive disorder. No statistically significant difference was obtained in these three groups in terms of irisin levels. Further studies may help to understand the role of irisin in the underlying mechanism of depression.