脑源性神经营养因子(Brain-derived neurotrophic factor，BDNF)前肽区多态性(Val66Met; rs6265)与认知水平显著相关。2型糖尿病（T2DM）患者存在认知多维度受损，也是Alzheimer病的独立危险因素之一，但其与BDNF基因多态性之间的关系尚不完全明确。脑影像学分析技术的发展为在体水平探索糖尿病认知障碍患者的神经网络机制提供了契机。本研究正基于此，在前期对T2DM 患者脑功能系列研究取得实质性进展的基础上，首次尝试将易感基因BDNF多态性与多模态MRI技术结合，揭示BDNF(Val66Met)多态性在糖尿病患者轻度认知障碍向Alzheimer病转化中的神经网络特征及机制，明确其作为早期预警糖尿病患者认知功能恶化基因影像学标记的可行性。本研究也必将为最终实现延缓甚至逆转糖尿病患者认知障碍的进展提供可靠的临床研究证据。

The propeptide region polymorphism of Brain-derived neurotrophic factor (BDNF) (Val66Met; rs6265) were significantly associated with cognitive function. Patients with type 2 diabetes mellitus (T2DM) have multiple dimensions of cognitive impairment, but their relationship with the BDNF gene polymorphism is still unclear. Development of brain neuroimaging techniques provide the opportunity for exploring the brain changes of diabetes. Based on the substantive results in our previous studies on the brain function in T2DM patients, for the first time, we curretly try to combine BDNF gene polymorphisms and multimodality MRI technologies in order to explore the role of BDNF gene polymorphism in the progress mechanism of cognitive impairment in T2DM patients. We aim to demonstrate whether BDNF gene polymorphism can be considered as a early predictor or a neuroimaging marker in cognitive decline of T2DM patients. Our results may contribute to early warning, and ultimately slow down or even reverse the progression of cognitive impairment in T2DM patients.