Serum Kynurenines Correlate With Depressive Symptoms and Disability in Poststroke Patients: A Cross-sectional Study

Background Poststroke depression (PSD) is related to adverse functional and cognitive prognosis in stroke patients. The participation of kynurenine pathway metabolites in depression has been previously proposed; however, there are few studies on its role in PSD and disability in stroke. Objective To investigate if there is a correlation between serum kynurenines levels with poststroke anxiety and depression symptoms and disability scales. Methods A cross-sectional case-control study was conducted in patients with first stroke, of >1 month and <1 year of evolution, with no history of previous psychiatric or neurological disorders; the Hospital Anxiety and Depression Scale (HADS), Montreal Cognitive Assessment (MoCA), functional evaluations (Barthel index, Functional Independence Measure [FIM]) were applied and serum kynurenines (Kyns) were determined. Results Sixty patients were included; significant depressive symptoms were found in 63% of the cases; a significant and positive correlation was obtained between levels of 3-hydroxykynurenine (3-HK) with HADS-T (r= 0.30,P= .025) and HADS-D (r= 0.28,P= .039). Depressed patients showed significantly higher levels of 3HK (P= .048) and KYNA (P= .0271) than nondepressed patients; the 3HK levels were inversely correlated with functional scales: Barthel index (r= -0.31,P= .02), FIM (r= -0.40,P= .01); in addition, serum 3HK levels were significantly higher in patients with poor sleep quality (P= .0190). Conclusions Serum Kyns show correlation with the presence and severity of depressive symptoms and with the disability and sleep quality. Kyns may be a potential marker of depression risk and disability in stroke in future.