2型糖尿病患者脑血流和功能连接变化及与记忆功能的关系

目的 纵向观察2型糖尿病(T2DM)患者脑血流量(CBF)及功能连接(FC)变化,分析CBF、FC与记忆功能的关系.方法 对27例T2DM患者(T2DM组)及36名健康志愿者(对照组)行头部MR检查及记忆功能测评,并于5年后随访复查.对CBF行重复测量方差分析,以CBF改变存在显著组别×时间交互效应的脑区作为种子点行F...

Changes of cerebral blood flow, functional connectivity and the relationships with memory function in type 2 diabetes mellitus

Objective To longitudinally observe the changes of cerebral blood flow (CBF) and functional connectivity (FC) in patients with type 2 diabetes mellitus (T2DM), and to analyze the relationships of these changes with memory function. Methods Twenty-seven T2DM patients (T2DM group) and 36 healthy volunteers (control group) underwent head MRI and memory assessments as well as the same examinations 5 years later. Then repeated measuring analysis of variance models was performed of CBF. Taken brain area with significant CBF interaction effect as the seed point, the interaction effects of whole brain FC were evaluated, and the correlations of CBF, FC and memory behavior indicators were analyzed. Results The group×time interaction effect was significant in bilateral occipital lobes (FDR corrected, P<0.05). The baseline CBF of occipital cortex was not significantly different between T2DM group and control group (P>0.05), but 5 years later, that in T2DM group was significantly lower than in control group (P<0.05). FC between the left V1 dorsal area (LV1d) of the visual cortex and bilateral temporal lobes showed significant interaction effect (FDR corrected, P<0.05). FC of the right temporal lobe at baseline in T2DM group was significantly higher than that in control group (P<0.05), whereas 5 years later, FC of bilateral temporal lobes were significantly decreased compared with baseline in T2DM group (both P<0.05). The baseline FC between the LV1d and the right temporal lobe in T2DM patients were positively correlated with short-time memory performances (r=0.446, P=0.033), and CBF 5 years later were positively correlated with forward digital span (r=0.493,P=0.012). Conclusion FC between the visual and auditory cortices compensatory increased in early stage T2DM patients. However, with the decrease of blood supply, FC compensation in the audiovisual cortex gradually decreased, which might be one of the neural mechanisms of the memory function decline in T2DM patients.