Evaluation of altered brain activity in type 2 diabetes using various indices of brain function: A resting-state functional magnetic resonance imaging study

Abstract

BackgroundType 2 diabetes mellitus (T2DM) has been identified as a risk factor that increases the rate of cognitive decline. Previous studies showed that patients with T2DM had brain function alterations based on a single index of resting-state functional magnetic resonance imaging (rs-fMRI). The present study aimed to explore spontaneous brain activity in patients with T2DM by comparing various rs-fMRI indices, and to determine the relationship between these changes and cognitive dysfunction.MethodsA total of 52 patients with T2DM and age- and sex-matched control participants were included in this study. The amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and voxel-mirrored homotopic connectivity (VMHC) values were calculated to represent the status of spontaneous neural activity. The Montreal Cognitive Assessment (MoCA) was used for the rapid evaluation of cognition in all subjects. Pearson correlation and mediation analyses were conducted to investigate the relationship between rs-fMRI indices and clinical parameters such as fasting glucose, disease duration, and MoCA.ResultsPatients with T2DM had alterations of concordant spontaneous brain activity in brain areas including the bilateral cerebellum posterior lobe, the left inferior temporal gyrus (ITG.L), the parahippocampal gyrus, and the left supplementary motor area (SMA.L). The indices were significantly correlated to each other in most of the detected brain areas. Positive correlations were observed between fasting glucose and neural activity in the surrounding areas of the left insula and the inferior frontal gyrus. MoCA scores were negatively correlated with the ReHo values extracted from the left anterior occipital lobe and the superior cerebellar cortex and were positively correlated with VMHC values extracted from the left caudate and the precentral gyrus (PreCG). No significant mediation effect of abnormal brain activity was found in the relationship between clinical parameters and MoCA scores.ConclusionThe current study demonstrated the functional concordance of abnormal brain activities in patients with T2DM by comparing ALFF, ReHo, and VMHC measurements. Widespread abnormalities mainly involved in motor and sensory processing functions may provide insight into examining T2DM-related neurological pathophysiology.

Alterations of spontaneous brain activity in type 2 diabetes mellitus without mild cognitive impairment: a resting-state functional magnetic resonance study

“…Each method contributed partly elucidating the functional abnormalities in T2DM patients. In line with previous research, our findings show that a combined usage of ALFF/ReHo/VMHC is rational and necessary ( Zhang et al, 2022 ). The absence of coexistence might be attributed to the intact cognitive function of the study cohort.…”

Altered cortical thickness-based structural covariance networks in type 2 diabetes mellitus

“…Previous studies have reported decreased DC and node efficiency in ITG ( Chen et al, 2017 ), and cortical atrophy in the ITG has been correlated with cognitive decline in T2DM patients ( Li et al, 2020 ). The inferior frontal junction plays a key role in controlling the spatially global effects of feature-based attention in the human visual area ( Zhang et al, 2018 ), and previous studies have shown abnormal neuronal activity ( Zhang et al, 2022 ) and decreased gray matter volume ( He et al, 2022 ) in the IFG regions in T2DM patients. Therefore, we speculate that impaired ventral visual pathways may be involved in the neural basis of visual cognitive impairment in T2DM patients, particularly visuospatial abnormalities.…”