Aberrant Brain Regional Homogeneity and Functional Connectivity in Middle-Aged T2DM Patients: A Resting-State Functional MRI Study

Abstract

Type 2 diabetes mellitus (T2DM) has been associated with cognitive impairment. However, its neurological mechanism remains elusive. Combining regional homogeneity (ReHo) and functional connectivity (FC) analyses, the present study aimed to investigate brain functional alterations in middle-aged T2DM patients, which could provide complementary information for the neural substrates underlying T2DM-associated brain dysfunction. Twenty-five T2DM patients and 25 healthy controls were involved in neuropsychological testing and structural and resting-state functional magnetic resonance imaging (rs-fMRI) data acquisition. ReHo analysis was conducted to determine the peak coordinates of brain regions with abnormal local brain activity synchronization. Then, the identified brain regions were considered as seeds, and FC between these brain regions and global voxels was computed. Finally, the potential correlations between the imaging indices and neuropsychological data were also explored. Compared with healthy controls, T2DM patients exhibited higher ReHo values in the anterior cingulate gyrus (ACG) and lower ReHo in the right fusiform gyrus (FFG), right precentral gyrus (PreCG) and right medial orbit of the superior frontal gyrus (SFG). Considering these areas as seed regions, T2DM patients displayed aberrant FC, mainly in the frontal and parietal lobes. The pattern of FC alterations in T2DM patients was characterized by decreased connectivity and positive to negative or negative to positive converted connectivity. Digital Span Test (DST) forward scores revealed significant correlations with the ReHo values of the right PreCG (ρ = 0.527, p = 0.014) and FC between the right FFG and middle temporal gyrus (MTG; ρ = −0.437, p = 0.048). Our findings suggest that T2DM patients suffer from cognitive dysfunction related to spatially local and remote brain activity synchronization impairment. The patterns of ReHo and FC alterations shed light on the mechanisms underlying T2DM-associated brain dysfunction and might serve as imaging biomarkers for diagnosis and evaluation.

Altered Brain Functional Hubs and Connectivity in Type 2 Diabetes Mellitus Patients: A Resting-State fMRI Study

“…Additionally, the patients with lower HbA 1c levels obtained higher scores on the DST forwards. The results were similar to those of several previous studies, which indicated that T2DM patients with elevated glycemic parameters exhibited decreased/inverted brain functional activity and poor cognitive performance (Xia et al, 2013 ; Chen et al, 2014 ; Liu D. et al, 2016 ; Yang et al, 2016 ). However, the findings of this study did not provide sufficient information about the relationships between the altered brain function and cognitive performance.…”

“…The brain regions where identified hubs are located have been reported to be abnormal in previous studies using other neuroimaging metrics in T2DM patients, which suggests that these brain regions are susceptible to T2DM. The ACG is usually identified as the disturbed brain region across experiments and appeared with increased amplitude of low-frequency fluctuation, regional homogeneity (Cui et al, 2014 ; Liu D. et al, 2016 ), and cerebral blood flow (Cui et al, 2017 ). The aforementioned hyperactivity of ACG has usually been regarded as a means to compensate for the cognitive loss and maintain normal cognition (He et al, 2015 ; Liu D. et al, 2016 ; Cui et al, 2017 ).…”

Functional MRI reveals effects of high intraocular pressure on central nervous system in high‐tension glaucoma patients

“…Besides the above discussion, ReHo value abnormalities in the FG were also seen in depression disorder (Liu et al. ; Shen et al. ).…”

Abnormal Regional Homogeneity and Functional Connectivity of Baseline Brain Activity in Hepatitis B Virus-Related Cirrhosis With and Without Minimal Hepatic Encephalopathy

“…In addition, the ReHo measure is usually used to characterize spontaneous brain activity at a limited anatomical distance, while the FC is applied to characterize the correlation of the functional patterns of blood oxygen level-dependent signals in between spatially distant brain areas at a network level. Thus, the two analyses, ReHo and FC, are considered to be mutually complementary for detecting both local and remote brain activity synchronization (Cui et al, 2016 ), and have conjunctively applied in other diseases (Liu et al, 2016 ). However, for functional networks in hepatitis B virus-related cirrhosis (HBV-RC) patients with or without MHE, abnormalities of regional and inter-regional function interaction patterns have not been well characterized either.…”

“…This study aimed to explore the local coherence of intrinsic brain activity and inter-regional connectivity features in patients with and without MHE by using ReHo and ROI-based FC analysis. Based on previous findings that there are abnormalities in both local brain activity and FC in one disease simultaneously (Liu et al, 2016 ; Lv et al, 2017 ), we hypothesized that: (1) regional disturbances of ReHo at both cortical and subcortical levels could be detected in HBV-RC patients with or without MHE; (2) the MHE/NMHE patients showed alterations in intrinsic functional connections between different ROI regions pairs; and (3) changes of ReHo and FC in specific functional networks might be correlated with the disease duration or neuropsychological performances measured by the PHES tests.…”