Clinical Significance Of Serum Levels Of Brain-derived Neuro-Trophic Factor In Patients Of Cognitive Impairment

Objective:To investigate the clinical significance of brain-derived neurotrophic factor (BDNF) from peripheral serum in patient s of Alzheimer's disease (AD) and vascular cognitive impairment(VCI).Methods: 27 out- and inpatient s of AD( including 16 mild AD and 11 moderate -severe AD) ,7 MCI-A and 25 VCI (including 9 MCI-V, 11 mild VD and 5 moderate -severe VD) were recriuted from 2009 October to 2010 November from The second Hospital of Hehei Medical University , 30 controls were recriuted simultaneously in health examinated people. Enzyme-linked immunosorbant assay ( ELISA) was used to measure the serum levels of BDNF.Results:1 Age, gender, education years and the level of BDNF showed no significantly difference between AD and control group (t=1.165,P=0.249;χ~2=0.203, P=0.653;χ~2=0.677,P=0.954;t=﹣1.844,P=0.071 respectively) .2 Age, gender and education years showed no significantly difference between VCI and control group (t=0.164,P=0.871;χ~2=0.010, P=0.921;χ~2=0.408, P=0.982 respectively) ,and the level of BDNF showed significantly difference(t=﹣2.195,P=0.033).3 Age, gender, education years and the level of BDNF showed no significantly difference between AD and VCI group (t=1.007,P=0.319;χ~2=0.277,P=0.598;χ~2=0.950,P=0.917;t=0.487,P=0.629 respectively).4 Age, gender, education years and the level of BDNF showed no significantly difference in MCI-A, mild AD and moderate -severe group (χ~2=6.111,P=0.635;χ~2=4.553,P=0.103;F=0.030,P=0.971; F=0.133,P=0.876 respectively). 5 Age, gender , education years and the level of BDNF showed no significantly difference in MCI-V, mild VD and moderate-severe group (F=0.675,P=0.519;χ~2=1.965,P=0.373;χ~2=8.793,P=0.360; F=0.087,P=0.917 respectively).Conclusions:1 The peripheral serum level of BDNF in AD was lower than control group, but there were no significant differences.Serum levels of BDNF could not be as a candidate marker for clinical diagnosis of AD.2 The peripheral serum level of BDNF in VCI was lower than control group, and there were significant differences. No significant differences were demonstrated in VCI and AD. BDNF might play a role in pathophysiology of VCI,but serum levels of BDNF could not distinguish VCI from AD.3 No significant differences were demonstrated in peripheral serum levels of BDNF among MCI-A, mild AD and moderate -severe AD group,as well as among MCI-V, mild VD and moderate -severe VD group. Serum levels of BDNF could not reflect the severity of AD or vascular cognitive impairment.