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 ( = 0.30, = .025) and HADS-D ( = 0.28, = .039). Depressed patients showed significantly higher levels of 3HK ( = .048) and KYNA ( = .0271) than nondepressed patients; the 3HK levels were inversely correlated with functional scales: Barthel index ( = -0.31, = .02), FIM ( = -0.40, = .01); in addition, serum 3HK levels were significantly higher in patients with poor sleep quality ( = .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.