Altered Functional Hubs and Connectivity in Type 2 Diabetes Mellitus Without Mild Cognitive Impairment.

Yifan Li,Yi Liang,Shijun Qiu,Yue Feng,Chunhong Qin,Xin Tan,Yuna Chen,Jinquan Yang,Xiaomeng Ma,Hui Zeng

doi:10.3389/fneur.2020.01016

Abstract

Background: Type 2 diabetes mellitus (T2DM)-related cognitive decline is associated with neuroimaging changes. However, only a few studies have focused on early functional alteration in T2DM prior to mild cognitive impairment (MCI). This study aimed to investigate the early changes of global connectivity patterns in T2DM by using a resting-state functional magnetic resonance imaging (rs-fMRI) technique.Methods: Thirty-four T2DM subjects and 38 age-, sex-, and education-matched healthy controls (HCs) underwent rs-fMRI in a 3T MRI scanner. Degree centrality (DC) was used to identify the functional hubs of the whole brain in T2DM without MCI. Then the functional connectivity (FC) between hubs and the rest of the brain was assessed by using the hub-based approach.Results: Compared with HCs, T2DM subjects showed increased DC in the right cerebellum lobules III–V. Hub-based FC analysis found that the right cerebellum lobules III–V of T2DM subjects had increased FC with the right cerebellum crus II and lobule VI, the right temporal inferior/middle gyrus, and the right hippocampus.Conclusions: Increased DC in the right cerebellum regions III–V, as well as increased FC within cerebellar regions and ipsilateral cerebrocerebellar regions, may indicate an important pathophysiological mechanism for compensation in T2DM without MCI.

Highlights

Type 2 diabetes mellitus (T2DM) is a systemic metabolic disease, resulting in severe complications of multiple systems
Results of the region of interest (ROI)-based functional connectivity (FC) analysis should be interpreted in caution, as the selected ROIs are mainly based on the prior knowledge, leading to different and unpredictable findings [13]
After Gaussian random field (GRF) multiple comparison correction, only one cluster survived in the T2DM group compared with the healthy control (HC) group in the brain areas with increased degree centrality (DC) (Table 2, Figure 1), involving the right cerebellum areas III– V

Summary

Introduction

Type 2 diabetes mellitus (T2DM) is a systemic metabolic disease, resulting in severe complications of multiple systems. Neuroimaging methods have been generally applied to probe the mechanism of T2DM-related cognitive impairment [7,8,9,10]. Only a few studies kept a watchful eye on the early neuroimaging changes in T2DM subjects without MCI, and the underlying mechanisms have not been entirely elaborated. Sun et al found that functional connectivity (FC) between the hippocampus and certain brain structures had decreased significantly in T2DM subjects without MCI [12]. Type 2 diabetes mellitus (T2DM)-related cognitive decline is associated with neuroimaging changes. Only a few studies have focused on early functional alteration in T2DM prior to mild cognitive impairment (MCI). This study aimed to investigate the early changes of global connectivity patterns in T2DM by using a resting-state functional magnetic resonance imaging (rs-fMRI) technique

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Conclusion