血清脑源性神经营养因子水平及其基因多态性与首发老年抑郁症认知功能的关系

Association between brain-derived neurotrophic factor serum level,gene polymorphisms and cognitive function in first-episode late-life depression

目的探求血清脑源性神经营养因子(BDNF)水平及其基因多态性与老年首发抑郁症患者认知功能障碍的关系。方法前瞻性连续纳入2014年4月至2016年1月首都医科大学附属北京安定医院门诊或住院的60岁及以上老年首发抑郁症患者。采用汉密尔顿抑郁量表(HAMD-17)、言语流畅性测验、连线测验A-B、Stroop字色测试和威斯康星卡片分类测试对患者进行抑郁症严重程度及认知功能的评定,采集患者静脉血测定血清BDNF水平,并提取DNA,测定BDNF rs6265基因单核苷酸多态性位点。结果共80例老年抑郁症患者纳入本研究。BDNF rs6265基因型与抑郁障碍严重程度无关(均P>0.05)。HAMD-17总分与言语流畅性测验、WCST持续性错误数呈负相关(r=-0.239、-0.226,均P<0.05)。rs6265 VAL/MET基因型的连线测验A-B表现较VAL/VAL基因型差[(62.0±18.9)分比(48.3±18.6)分],差异有统计学意义(P<0.05)。血清BDNF水平与认知功能之间无相关性(均P>0.05),与HAMD-17评分呈负相关(r=-0.23,P<0.05)。结论BDNF rs6265基因多态性与老年抑郁症患者认知功能损害相关,而与BDNF水平无显著关联,提示BDNF可能通过其他机制影响老年抑郁症认知功能。

Objective To examine the associations between the brain-derived neurotrophic factor(BDNF)level,gene polymorphism,and cognitive function in patients with late-life depression.Methods From April 2014 to January 2016,inpatients or outpatients over and 60 years old with first-episode depression from Beijing Anding Hospital affiliated to Capital Medical University were enrolled in this study.The severity of depression and cognitive function were assessed using Hamilton Depression Scale(HAMD-17),the verbal fluency test,trail making tests(TMT)A-B,the Stroop color-word test and Wisconsin card sorting test.Blood samples were collected to determine the level of serum BDNF,and DNA was extracted to determine the single nucleotide polymorphism(SNP)of BDNF rs6265 gene.Rusults A total of 80 patients were enrolled in this study.No significant associations were found between BDNF rs6265 and the severity of depression(P>0.05).The total score of HAMD-17 was negatively correlated with verbal fluency test and WCST persistent errors(r=-0.239,-0.226),and the differences were statistically significant(P<0.05).Patients with VAL/MET on rs6265 performed significantly worse on TMT A-B than that in patients with VAL/VAL(P<0.05).The serum BDNF is not significantly correlated to cognitive function(P>0.05),while it is negatively correlated with the HAMD-17 total score(P<0.05).Conclusions BDNF rs6265 gene polymorphism is associated with cognitive impairment in patients with late-life depression,but not with BDNF level,suggesting that BDNF may affect cognitive function in elderly depression through other mechanisms.