Objective To explore the differences of regional homogeneity(ReHo)between overweight and normal weight male patients with type 2 diabetes mellitus(T2DM)during rest and their correlations with clinical features.Methods Twenty-five untreated male overweight T2DM(OW-T2DM)patients,25 untreated male normal weight T2DM(NW-T2DM)patients and 25 healthy controls(HC)were enrolled.The brain structure and resting-state functional magnetic resonance imaging(rs-fMRI)data were collected from all subjects.The brain structure and rs-fMRI data were preprocessed,and ReHo values of all brain regions were calculated for all subjects.ReHo values were compared among three groups and between groups respectively via the methods of one-way analysis of variance and two-sample t-test.To address the problem of multiple comparisons,the method of AlphaSim was performed(the threshold was set at P<0.005,the number of voxel clusters was>12).In addition,Pearson correlation analysis was performed to explore the relationships between ReHo values of the abnormal brain regions and clinical features in patients.Results(1)The brain regions showed differences of ReHo values among three groups were mainly distributed in the right hemisphere,including the superior parietal gyrus,superior marginal gyrus and superior occipital gyrus;(2)Compared with HC,NW-T2DM patients showed significantly decreased ReHo values in the right medial superior frontal gyrus,right middle cingulate gyrus and left anterior cingulate gyrus;(3)Compared with HC,OW-T2DM patients showed significantly decreased ReHo values in the bilateral postcentral gyrus and bilateral middle cingulate gyrus;(4)Compared with NW-T2DM patients,OW-T2DM patients showed significantly decreased ReHo values in the right superior parietal gyrus,right superior occipital gyrus and left cuneus;(5)ReHo values of the right medial superior frontal gyrus and right superior parietal gyrus were negatively correlated with hemoglobinA1c(HbA1c)level and body mass index(BMI),respectively,in all patients.Conclusion The occurrence of T2DM in male patients may lead to the declined activity of brain regions located in the default mode network(DMN),while overweight may further lead to decreased brain activity within the attention and visual recognition network in male T2DM patients.