Resting-state functional magnetic resonance imaging shows altered brain network topology in Type 2 diabetic patients without cognitive impairment

Abstract

We analyzed topology of brain functional networks in type 2 diabetes mellitus (T2DM) patients without mild cognitive impairment. We recruited T2DM patients without mild cognitive impairment (4 males and 8 females) and healthy control subjects (8 males and 16 females) to undergo cognitive testing and resting-state functional magnetic resonance imaging. Graph theoretical analysis of functional brain networks revealed abnormal small-world architecture in T2DM patients as compared to control subjects. The functional brain networks of T2DM patients showed increased path length, decreased global efficiency and disrupted long-distance connections. Moreover, reduced nodal characteristics were distributed in the frontal, parietal and temporal lobes, while increased nodal characteristics were distributed in the frontal, occipital lobes, and basal ganglia in the T2DM patients. The disrupted topological properties correlated with cognitive performance of T2DM patients. These findings demonstrate altered topological organization of functional brain networks in T2DM patients without mild cognitive impairment.

Altered brain structural topological properties in type 2 diabetes mellitus patients without complications

“…We also observed a T2DM‐related increase in nodal degree of the right inferior frontal gyrus. Similar results were reported in a recent study of topological networks based on functional MRI, in which increased betweenness of the inferior frontal gyrus in T2DM patients was found . The prefrontal cortex is a critical structure for cognitive function.…”

“…A short average path length in a WM network facilitates rapid information transfer between different brain regions, which is the basis of cognitive processes . The increased λ in T2DM patients in the present study may reflect disrupted network integration, which is consistent with previous studies on T2DM patients . In T2DM patients, λ was negatively correlated with the ACC of the spatial working memory task, which may reflect that patients with increased λ are worse at dealing with spatial working memory tasks.…”

“…In T2DM patients, λ was negatively correlated with the ACC of the spatial working memory task, which may reflect that patients with increased λ are worse at dealing with spatial working memory tasks. The changing patterns of clustering coefficients reported in topological network studies on T2DM are not consistent . For example, some studies reported a decreased clustering coefficient in T2DM patients, whereas others reported an increase or no change .…”

“…37 The increased λ in T2DM patients in the present study may reflect disrupted network integration, which is consistent with previous studies on T2DM patients. [14][15][16]38 In T2DM patients, λ was negatively correlated with the ACC of the spatial working memory task, which may reflect that patients with increased λ are worse at dealing with spatial working memory tasks. The changing patterns of clustering coefficients reported in topological network studies on T2DM are not consistent.…”

“…The changing patterns of clustering coefficients reported in topological network studies on T2DM are not consistent. [14][15][16]38,39 For example, some studies reported a decreased clustering coefficient in T2DM patients, 14,15,38 whereas others reported an increase 39 or no change. 16 In the present study, the network clustering coefficient in T2DM patients was found to be increased.…”