Altered baseline brain activity in type 2 diabetes: a resting-state fMRI study

Area of Science:

• Neuroscience
• Endocrinology
• Medical Imaging

Background:

• Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder with known systemic effects.
• Emerging evidence suggests T2DM may also impact brain structure and function, potentially affecting cognitive abilities.
• Resting-state functional magnetic resonance imaging (rs-fMRI) offers a non-invasive method to investigate baseline brain activity.

Purpose of the Study:

• To determine if individuals with T2DM display altered baseline brain activity compared to healthy controls.
• To investigate the relationship between neural activity in the middle temporal gyrus (MTG) and cognitive performance in T2DM patients.
• To explore correlations between brain activity measures and key clinical indicators of diabetes severity and pancreatic function.

Main Methods:

• Utilized rs-fMRI to compare brain activity in 28 T2DM patients and 29 matched healthy controls.
• Quantified spontaneous neuronal activity using the amplitude of low-frequency fluctuations (ALFF) of fMRI signals.
• Correlated ALFF values with clinical data, including HbA1c, cognitive test scores, C-peptide levels, and beta-cell function.

Main Results:

• T2DM patients showed significantly reduced ALFF in the bilateral MTG, left fusiform gyrus, left middle occipital gyrus, and right inferior occipital gyrus.
• Increased ALFF was observed in the bilateral cerebellum posterior lobe and right cerebellum culmen in T2DM patients.
• ALFF in the MTG was inversely correlated with HbA1c and Trail Making Test-B scores, and positively correlated with C-peptide levels and beta-cell function.

Conclusions:

• T2DM is associated with widespread alterations in brain activity, as measured by ALFF.
• These neural changes correlate with poorer cognitive function, higher glycemic burden, and impaired pancreatic beta-cell function.
• Disturbances in MTG ALFF may be a key factor in T2DM-related cognitive decline and could serve as a potential biomarker.