2型糖尿病执行功能损害的脑铁代谢研究

Study on brain iron metabolism in T2DM patients with executive function damage

目的:利用定量磁化率图(QSM)研究2型糖尿病(T2DM)患者脑铁含量分布差异,并与健康老年人的作比较,探究T2DM患者认知功能损伤与脑铁沉积的关系。方法:本研究纳入T2DM患者32名,健康志愿者(HC)32名,采集所有受试者的磁共振图像并且对其认知功能进行评测,经后处理获得定量磁化率图(QSM)数据,通过ITK-SNAP软件测量脑灰质核团及全脑白质的磁化率值以反映脑铁含量,最后将认知功能得分与QSM所测磁化率值进行比较。结果:T2DM组的MoCA评分显著低于HC组(P=0.003),在SCWT-C方面,T2DM组用时较HC组明显延长(P=0.003),提示T2DM组执行功能更差。在灰质核团磁化率值比较中,T2DM组壳核磁化率值显著高于HC组(P<0.001),T2DM组丘脑、苍白球、尾状核、红核、黑质磁化率值与HC组无显著统计学差异。通过对两组患者脑白质磁化率比较时发现T2DM组枕叶白质磁化率值(P<0.001)及全脑白质总磁化率平均值(P=0.002)均较HC组更高,T2DM组额叶、顶叶、颞叶、放射冠、内囊前肢、内囊后肢、胼胝体膝部和胼胝体压部磁化率值较HC组无统计学差异。结论:T2DM患者壳核、枕叶白质及全脑白质总磁化率平均值升高与认知-执行功能降低有明显相关性,QSM测定壳核铁沉积可作为T2DM患者中枢神经系统损伤的影像标志物。

Objective:Quantitative susceptibility mapping(QSM)was used to study the distribution of brain iron content in T2DM patients and compared with that of healthy elderly to explore the relationship between cognitive dysfunction and brain iron deposition in T2DM patients.Methods:32 T2DM patients and 32 healthy controls(HC)were recruited in our study.Magnetic resonance images(MRI)and their cognitive function of all subjects were collected.With the preprocessed QSM data,the susceptibility value of the region of interest(ROI)was measured by ITK-SNAP to reflect the iron content.Finally,the scores of cognitive function were compared with the magnetic susceptibility values measured by QSM.Results:The MoCA scores of T2DM group were significantly lower than that of HC group,and the durations of SCWT-C in T2DM group were significantly longer than that in HC group(P=0.003),suggesting that the executive function of T2DM group was lower.In the comparison of magnetic susceptibility of gray matter nucleus,the magnetic susceptibility of putamen in T2DM group was significantly higher than that in HC group(P<0.001)and there were no significant differences in magnetic susceptibility of thalamus,globus pallidus,caudate nucleus,red nucleus and substantia nigra between T2DM group and HC group.By comparing the magnetic susceptibility of white matter(WM)between the two groups,it was found that the magnetic susceptibility of occipital WM(P<0.001)and the average values of total magnetic susceptibility of whole brain WM(P=0.002)in T2DM group were higher than those in HC group.In addition,there were no significant differences in magnetic susceptibility in frontal lobe,parietal lobe,temporal lobe,crown radiata,anterior and posterior limb of internal capsule,genu and splenium of corpus callosum between T2DM group and HC group.Conclusion:The increase of average values of total magnetic susceptibility in putamen,occipital WM and whole brain WM in T2DM patients was significantly correlated with the decrease of cognitive and executive function.Iron deposition in putamen measured by QSM can be used as an imaging marker of central nervous system injury in T2DM patients..