Structural Imaging Study Of Weight-related Lateralized Hemisphere Atrophy In Patients With Type 2 Diabetes Mellitus

Purpose: By analyzing of the changes of asymmetry index(AI)on brain structural parameters in patients between type 2 diabetes mellitus(T2DM)and T2 DM with obesity,this study explored the imaging features of T2 DM and obesity caused by lateralized hemisphere atrophy and whether the impact or reversal of lateralized brain atrophy in the combined obesity group made by T2 DM,in order to further understand the pathogenesis of T2 DM with obesity related complications.Materials and Methods: A total of 145 subjects from the Radiological Imaging Center at the First Affiliated Hospital of University of South China were enrolled in this study.All of them underwent 3.0T MRI examination and related scale evaluation.According to the presence or absence of T2 DM and obesity,they were divided into three groups:T2DM with obesity group(45 individuals),T2 DM without obesity group(39 individuals),and non-diabetic control group(61 individuals).Free Surfer,a brain structure image processing software,was employed to analyze grey matter volume(GMV),surface area(SA),cortical thickness(CT),mean curvature(MC),sulcus depth(SD),and local gyrification index(LGI)of 34 brain regions on the left and right hemisphere of the subjects.Result:(1)Comparison between the T2 DM group and the non-diabetic healthy control group: there are significant differences in the GMV of postcentral cortex(Po CG),bankssts,entorhinal cortex(EC),parsorbitalis,the CT of pars triangularis,lateral occipital gyrus,parsorbitalis,the SA of the inferior parietal gyrus,,lateral occipital gyrus,middle temporal gyrus(MTG),precuneus and caudal middle frontal gyrus(c MFG),the MC of inferior temporal gyrus(ITG)and lateral occipital gyrus,the LGI of parsorbitalis,caudal anterior cingulate cortex(c ACC),and Po CG(p<0.05),including increased GMV of parsorbitalis that showed a leftward asymmetry,while increased GMV of the Po CG,bankssts,EC that showed a rightward asymmetry;The parsorbitalis displays a leftward asymmetry and the larger thickness,and a rightward asymmetry was prominent in the decreased CT of pars triangularis and lateral occipital gyrus;The SA of the the inferior parietal gyrus,lateral occipital gyrus,MTG and c MFG increased with rightward asymmetry.However,the SA of the precuneus decreased with rightward asymmetry;the MC of ITG was found decreased and rightward asymmetry.On the contrary,the MC of the lateral occipital gyrus was increased and rightward asymmetry.In the diabetic group,the LGI of c ACC manifest decreased and rightward asymmetry,but the LGI of parsorbitalis and Po CG were with the trend of rightward asymmetry and an increase.(2)Comparison of overweight/obesity and without overweight/obesity in T2 DM group: there are significant differences in the CT of the insula,the SA of the medial orbitofrontal gyrus(m OFC),the MC of rostral anterior cingulate cortex(r ACC)and the SD of the insula and r ACC(p<0.05),including the CT of the insula showing a leftward and an increase;the SA of the m OFC displaying the decrease rightward asymmetry;the MC of r ACC displays leftward asymmetry and reduced.Moreover,SD in the r ACC was found increased and rightward asymmetry,while the SD of the insula is with a decrease and leftward.(3)Compared with the large normal population of Kong,X.Z: the CT of pars triangularis,the SA of lateral occipital gyrus and c MFG,and the SA of m OFC all showed rightward asymmetry to the contrary,in the comparison between the T2 DM group and the non-diabetic healthy control group;the SA of m OFC showed rightward asymmetry to the contrary,in the comparison of overweight/obesity and without overweight/obesity in T2 DM group.Conclusions:(1)Caudal middle frontal gyrus,pars triangularis,parsorbitalis,entorhinal cortex,bankssts,middle temporal gyrus,inferior temporal gyrus,postcentral cortex,inferior parietal gyrus,lateral occipital lobe,precuneus and caudal anterior cingulate,may be the affected brain regions of T2DM;(2)Insula,medial orbitofrontal gyrus and rostral anterior cingulate cortex may be the effect brain regions of overweight/obesity;(3)Pars triangularis,lateral occipital gyrus and c MFG are probable to be lateralization of encephalic regions affected by T2DM;m OFC is probable to be lateralization of encephalic regions affected by overweight/obesity in patients with T2 DM.