Section on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China.
Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Mol Psychiatry. 2017 Feb;22(2):312-320. doi: 10.1038/mp.2016.62. Epub 2016 Apr 26.
Studies suggest that dysfunction of brain-derived neurotrophic factor (BDNF) is a possible contributor to the pathology and symptoms of Alzheimer's disease (AD). Several studies report reduced peripheral blood levels of BDNF in AD, but findings are inconsistent. This study sought to quantitatively summarize the clinical BDNF data in patients with AD and mild cognitive impairment (MCI, a prodromal stage of AD) with a meta-analytical technique. A systematic search of Pubmed, PsycINFO and the Cochrane Library identified 29 articles for inclusion in the meta-analysis. Random-effects meta-analysis showed that patients with AD had significantly decreased baseline peripheral blood levels of BDNF compared with healthy control (HC) subjects (24 studies, Hedges' g=-0.339, 95% confidence interval (CI)=-0.572 to -0.106, P=0.004). MCI subjects showed a trend for decreased BDNF levels compared with HC subjects (14 studies, Hedges' g=-0.201, 95% CI=-0.413 to 0.010, P=0.062). No differences were found between AD and MCI subjects in BDNF levels (11 studies, Hedges' g=0.058, 95% CI=-0.120 to 0.236, P=0.522). Interestingly, the effective sizes and statistical significance improved after excluding studies with reported medication in patients (between AD and HC: 18 studies, Hedges' g=-0.492, P<0.001; between MCI and HC: 11 studies, Hedges' g=-0.339, P=0.003). These results strengthen the clinical evidence that AD or MCI is accompanied by reduced peripheral blood BDNF levels, supporting an association between the decreasing levels of BDNF and the progression of AD.
研究表明，脑源性神经营养因子（BDNF）功能障碍可能是阿尔茨海默病（AD）发病机制和症状的一个促成因素。多项研究报告 AD 患者外周血 BDNF 水平降低，但结果不一致。本研究采用荟萃分析技术，定量总结 AD 和轻度认知障碍（MCI，AD 的前驱阶段）患者的临床 BDNF 数据。系统检索 Pubmed、PsycINFO 和 Cochrane 图书馆，共纳入 29 项研究进行荟萃分析。随机效应荟萃分析显示，与健康对照组（HC）相比，AD 患者的外周血 BDNF 基线水平显著降低（24 项研究，Hedges'g=-0.339，95%置信区间（CI）=-0.572 至-0.106，P=0.004）。与 HC 相比，MCI 患者的 BDNF 水平呈下降趋势（14 项研究，Hedges'g=-0.201，95%CI=-0.413 至 0.010，P=0.062）。AD 和 MCI 患者的 BDNF 水平无差异（11 项研究，Hedges'g=0.058，95%CI=-0.120 至 0.236，P=0.522）。有趣的是，排除有报道患者用药的研究后，有效大小和统计学意义有所提高（AD 与 HC 之间：18 项研究，Hedges'g=-0.492，P<0.001；MCI 与 HC 之间：11 项研究，Hedges'g=-0.339，P=0.003）。这些结果进一步证实了 AD 或 MCI 患者外周血 BDNF 水平降低的临床证据，支持 BDNF 水平下降与 AD 进展之间的关联。
