Original Research ARTICLE
A Post-hoc Study of D-amino Acid Oxidase in Blood as an Indicator of Post-stroke Dementia
- 1Department of Neurology, Linkou Chang Gung Memorial Hospital, Taiwan
- 2Center for Neuropsychiatric Research, National Health Research Institutes, Taiwan
- 3Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Taiwan
- 4Departmentr of Medicine, College of Medicine, Chang Gung University, Taiwan
Stroke is an important risk factor for dementia. Epidemiological studies have indicated a high incidence of dementia in stroke patients. There is currently no effective biomarker for the diagnosis of post-stroke dementia (PSD). D-amino acid oxidase (DAO) is a flavin-dependent enzyme widely distributed in the central nervous system. DAO oxidizes D-amino acids, a process which generates neurotoxic hydrogen peroxide and leads to neurodegeneration. This study aimed to examine post-stroke plasma DAO levels as a biomarker for PSD. In total, 53 patients with PSD, 20 post-stroke patients without dementia (PSNoD), and 71 age- and gender-matched normal controls were recruited. Cognitive function was evaluated at more than 30 days post-stroke. Plasma DAO was measured using the enzyme-linked immunosorbent assay. White matter hyperintensity (WMH), a neuroimaging biomarker of cerebral small vessel diseases, was determined by magnetic resonance imaging. We found that plasma DAO levels were independently higher in PSD subjects than in PSNoD subjects or the controls and were correlated with the WMH load in stroke patients. Using an area under the curve (AUC)/receiver operating characteristic analysis, plasma DAO levels were significantly reliable for the diagnosis of PSD. The sensitivity and specificity of the optimal cut-off value of 321 ng/ml of plasma DAO for the diagnosis of PSD were 75% and 88.7%, respectively. In conclusion, our data support that plasma DAO levels were increased in PSD patients and correlated with brain WMH, independent of age, gender, hypertension, and renal function. Plasma DAO levels may therefore aid in PSD diagnosis.
Keywords: D-amino acid oxidase (DAO), Stroke, Dementia, biomarker, post-stroke dementia, Cerebral Infarction
Received: 29 Oct 2018;
Accepted: 03 Apr 2019.
Edited by:Anna Rosell, Vall d'Hebron Research Institute (VHIR), Spain
Reviewed by:Iolanda Riba, Vall d'Hebron University Hospital, Spain
Milija Mijajlovic, Neurology clinic, Clinical Center of Serbia, Serbia
Copyright: © 2019 Chen, Chou, Tsou, Fang, Liu, Tsao, Hsu, Weng, Wang and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: PhD. Yu-Li Liu, Center for Neuropsychiatric Research, National Health Research Institutes, Zhunan, 35053, Taiwan, email@example.com