Structural Imaging Study Are Altered In Cognitive Function And Brain Reward Circuit Sub-region Of Type 2 Diabetes

Objective: To investigate the cortical and subcortical gray matter abnormalities in T2 DM patients with or without cognitive impairment,especially in reward circuit.The correlation between cortical or subcortical gray matter abnormalities in reward circuit and cognitive function were evaluated by structural MRI,and to reveal the neuroimaging mechanism of cognitive impairment in T2 DM patients.Materials and Methods: One hundred and thirteen subjects,including 49 patients with T2DM(17 T2 DM patients with cognitive impairment,32 T2 DM patients without mild cognitive impairment),were recruited and compared to 64 normal controls(40 males and 24 females),were recruited from the outpatient department and inpatient department of the First Affiliated Hospital of University of South China from 2017 to 2019.All participants underwent three-dimensional T1-weighted MRI images by using Philips Achieva 3.0-Tesla.We segmented volumes of several subcortical structures and cortical structures using FreeSurfer integrated registration and segmentation tool.We used partial correlation analyses with age,gender and education as confounding factors to assess the relationships between the abnormal network connectivity and the MMSE scores.Results: Patients with T2 DM had cortical thinning in the left caudal middle frontal cortex,left isthmus cingulate,left lateral orbitofrontal,left pars opercularis,left pars triangularis,left rostral middle frontal,right caudal anterior cingulate,right fusiform,right inferior parietal,right isthmus cingulate,right lateral orbitofrontal,right medial orbitofrontal,right middle temporal,right pars orbitalis,right posterior cingulate,right superior frontal.Compare with the T2 DM patients without cognitive impairment,reduced subregions in the subcortical structure volume were distributed in the bilateral thalamus proper,left putamen,the bilateral accumbens,right caudate,right amygdala in the T2 DM patients with cognitive impairment.Moreover,the T2 DM patients showed left isthmus cingulate thickness related to HbA1 c.In addition,the T2 DM patients with cognitive impairment showed left accumbens volume related to MMSE.Conclusion: Cortical and subcortical gray matter abnormalities are associated with cognitive status in patients with T2 DM,especially in reward circuits.It may suggest that the physiological mechanism of the reward network pathway may be the same as that of cognitive dysfunction in type 2 diabetes patients,so we can prevent and treat cognitive dysfunction in type 2 diabetes by intervening in the reward circuits pathway.