Concomitant functional impairment and reorganization in the linkage between the cerebellum and default mode network in patients with type 2 diabetes mellitus.

Background Increasing evidence shows that the default mode network (DMN) and cerebellum are prone to structural and functional abnormalities in patients with type 2 diabetes mellitus (T2DM). However, the type of change in the functional connection between the DMN and cerebellum is still unknown. Methods In this study, seed-based functional connectivity (FC) analysis was used to examine the intrinsic FC of the cerebellum-DMN between healthy controls (HCs) and T2DM patients. Pearson correlation analysis was used to explore the relationship between clinical variables and changes in FC. Results Compared with HCs, T2DM patients showed significantly increased FC of the left crus I-left medial superior frontal gyrus, left crus I-right medial superior frontal gyrus, and right crus I-left medial orbitofrontal cortex. Compared with HCs, T2DM patients showed decreased FC of the lobule IX-the right angular gyrus. Moreover, diabetes duration was positively correlated with increased FC of the left crus I-right medial superior frontal gyrus (r=0.438, P=0.007). Conclusions Concomitant functional impairment and reorganization in the linkage between the cerebellum and DMN in patients with T2DM may be a biomarker of early brain damage that can help us better understand the pathogenesis of cognitive impairment in T2DM.