A multimodal meta-analysis of regional structural and functional brain alterations in type 2 diabetes

•Multimodal meta-analyses of VBM and rs-fMRI studies were conducted in T2DM.•Conjoint decreased gray matter volume and hypoactivity showed in the DMN.•There was also dissociated GMV reduction and altered function in widespread areas.•Meta-analysis of global gray matter volume studies of T2DM were also performed.•These complicated patterns provide new insight into the neuropathology of T2DM. Neuroimaging studies have identified brain structural and functional alterations of type 2 diabetes mellitus (T2DM) patients; however, there is no systematic information on the relations between abnormalities in these two domains. We conducted a multimodal meta-analysis of voxel-based morphometry and regional resting-state functional MRI studies in T2DM, including fifteen structural datasets (693 patients and 684 controls) and sixteen functional datasets (378 patients and 358 controls). We found, in patients with T2DM compared to controls, conjoint decreased regional gray matter volume (GMV) and altered intrinsic activity mainly in the default mode network including bilateral superior temporal gyrus/Rolandic operculum, left middle and inferior temporal gyrus, and left supramarginal gyrus; decreased GMV alone in the limbic system; and functional abnormalities alone in the cerebellum, insula, and visual cortex. This meta-analysis identified complicated patterns of conjoint and dissociated brain alterations in T2DM patients, which may help provide new insight into the neuropathology of T2DM.