Altered Intranetwork and Internetwork Functional Connectivity in Type 2 Diabetes Mellitus With and Without Cognitive Impairment

Abstract

Type 2 diabetes mellitus (T2DM) is associated with cognitive impairment. We investigated whether alterations of intranetwork and internetwork functional connectivity with T2DM progression exist, by using resting-state functional MRI. MRI data were analysed from 19 T2DM patients with normal cognition (DMCN) and 19 T2DM patients with cognitive impairment (DMCI), 19 healthy controls (HC). Functional connectivity among 36 previously well-defined brain regions which consisted of 5 resting-state network (RSN) systems [default mode network (DMN), dorsal attention network (DAN), control network (CON), salience network (SAL) and sensorimotor network (SMN)] was investigated at 3 levels (integrity, network and connectivity). Impaired intranetwork and internetwork connectivity were found in T2DM, especially in DMCI, on the basis of the three levels of analysis. The bilateral posterior cerebellum, the right insula, the DMN and the CON were mainly involved in these changes. The functional connectivity strength of specific brain architectures in T2DM was found to be associated with haemoglobin A1c (HbA1c), cognitive score and illness duration. These network alterations in intergroup differences, which were associated with brain functional impairment due to T2DM, indicate that network organizations might be potential biomarkers for predicting the clinical progression, evaluating the cognitive impairment, and further understanding the pathophysiology of T2DM.

Biomarkers for cognitive decline in patients with diabetes mellitus: evidence from clinical studies

“…They concluded that the anterior-posterior connectivity dysfunction in diabetes might contributed to cognitive impairment. In diabetic patients with MCI, Yang et al [ 98 ] found disturbed intranetwork and internetwork functional connectivity DMN region, CON region, right insula and posterior cerebellum. These dysfunctions were positively correlated with HbA1c and DM duration, indicating the key role of hyperglycemia in the process of cognitive decline.…”

Application of neurite orientation dispersion and density imaging to characterize brain microstructural abnormalities in type‐2 diabetics with mild cognitive impairment

“…Decreased hippocampal functional connectivity with the bilateral frontal cortex has been found for T2DM patients without MCI . Yang et al compared T2DM subjects with and without cognitive impairment with healthy controls, and found impaired intranetwork and internetwork connectivities, especially in those with MCI . The underlying brain structural changes associated with the functional abnormalities of T2DM patients with cognitive impairment have attracted increasing attention as well.…”

“…[6][7][8] Some previous studies focused not only on the comparison between T2DM subjects and healthy controls, but also on the differences between those with and without cognitive impairment. 8,9 Decreased hippocampal functional connectivity with the bilateral frontal cortex has been found for T2DM patients without MCI. 7 Yang et al compared T2DM subjects with and without cognitive impairment with healthy controls, and found impaired intranetwork and internetwork connectivities, especially in those with MCI.…”

“…7 Yang et al compared T2DM subjects with and without cognitive impairment with healthy controls, and found impaired intranetwork and internetwork connectivities, especially in those with MCI. 8 The underlying brain structural changes associated with the functional abnormalities of T2DM patients with cognitive impairment have attracted increasing attention as well. Decreased gray matter volume was identified and more extensive atrophy was observed in T2DM patients with MCI.…”

Cerebral Pathology and Cognition in Diabetes: The Merits of Multiparametric Neuroimaging

“…Altered network and structural connectivity in type 2 diabetes have been shown using tractography (Reijmer et al, 2013a,b; Hoogenboom et al, 2014; van Bussel et al, 2016b; Yang et al, 2016; Zhang J. et al, 2016). Local and global network properties (i.e., cluster coefficient, global efficiency, path length) were altered and associated with impaired processing speed (Reijmer et al, 2013b).…”