Students Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran; NeuroImaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
Systematic Review and Meta-analysis Expert Group (SRMEG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
Brain Res. 2019 Feb 1;1704:127-136. doi: 10.1016/j.brainres.2018.10.006. Epub 2018 Oct 6.
Brain-derived neurotrophic factor (BDNF) is an abundant neurotrophin in the adult brain. Serum BDNF levels might be used as a proxy for its central expression. Considering conflicting reports, we aimed to answer "How do serum/CSF levels of BDNF change in patients with PD?".
We conducted a comprehensive search in MEDLINE, EMBASE and SCOPUS databases including 12 eligible studies. Five studies compared BDNF in serum of PD patients versus healthy controls (HC) and 3 studies provided BDNF levels in sera of non-depressed and depressed PD patients (NDPD and DPD). Review Manager and Software version 3.0 were used for meta-analysis and meta-regressions. Mean difference (MD) was used for measurement of effect size.
PD patients had reduced serum BDNF levels compared to HC (MD = -2.99 ng/mL). Serum BDNF was highest in DPD patients compared to HC (MD = -4.83 ng/mL), with no difference between DPD and NDPD patients in serum BDNF levels. Among co-variates that were eligible for meta-regression, age, sex, and Hoehn and Yahr (H&Y) motor stage had significant positive associations with the effect size in the difference of serum BDNF between patients and HC.
PD patients had reduced serum BDNF levels compared to HC, regardless of presence of co-morbid depression. PD is at least equally effective in reducing serum BDNF levels as depression. Motor progression predicts serum BDNF downregulation in PD. Acute exercise improves motor function and depressive symptoms in PD probably via BDNF upregulation. The paradoxical rise in serum BDNF in advance PD is probably compensatory in nature.
脑源性神经营养因子（BDNF）是成年人大脑中丰富的神经营养因子。血清 BDNF 水平可以作为其中枢表达的替代物。考虑到相互矛盾的报告，我们旨在回答“PD 患者的血清/CSF 中的 BDNF 水平如何变化？”。
我们在 MEDLINE、EMBASE 和 SCOPUS 数据库中进行了全面搜索，共纳入了 12 项符合条件的研究。其中 5 项研究比较了 PD 患者与健康对照者（HC）的血清 BDNF 水平，3 项研究提供了非抑郁和抑郁 PD 患者（NDPD 和 DPD）的血清 BDNF 水平。使用 Review Manager 和版本 3.0 软件进行荟萃分析和荟萃回归。使用均数差值（MD）来衡量效应大小。
与 HC 相比，PD 患者的血清 BDNF 水平降低（MD=-2.99ng/mL）。与 HC 相比，DPD 患者的血清 BDNF 水平最高（MD=-4.83ng/mL），而 DPD 和 NDPD 患者的血清 BDNF 水平无差异。在适合进行荟萃回归的协变量中，年龄、性别和 Hoehn 和 Yahr（H&Y）运动分期与患者和 HC 之间血清 BDNF 差异的效应大小呈显著正相关。
与 HC 相比，PD 患者的血清 BDNF 水平降低，无论是否存在共病抑郁。PD 在降低血清 BDNF 水平方面与抑郁同样有效。运动进展预测 PD 中血清 BDNF 的下调。急性运动通过 BDNF 上调改善 PD 中的运动功能和抑郁症状。在 PD 前期血清 BDNF 的反常升高可能是代偿性的。
