Arun Rajendran1,2, Madhurima Datta1,2, Saurabh Garg1,2, Soojin Lee1,2, Thanh-Duc Nguyen1,2, Nasrin Akbari1,2, Saqib Basar1,2, Ahmed Gouda1,2, Yosef Chodakiewitz2, Daniel Durand2 and Sam Hashemi1,2
1Vigilance Health Imaging Network Inc, Vancouver, Canada
2Prenuvo Inc, Vancouver, Canada
Purpose: This study aims to investigate the link between Type 2 Diabetes Mellitus (T2DM) and brain volume, while controlling for age, gender, and visceral fat distribution.
Materials and Methods: The study analyzed whole-body MRIs (WB-MRI) acquired at 1.5 T from 341 patients with T2DM and compared with 338 non diabetics matching for age, gender and visceral fat distribution. Brain volumes were segmented into 96 regions using FastSurfer, with normalization by intracranial volume. Visceral fat (vfat) volume was segmented using 3D nnU-Net model. T-tests were used to compare mean total brain volumes, including gray and white matter zones, lobes (frontal, temporal, parietal, and occipital), and Alzheimer’s prone regions (i.e., hippocampus, posterior cingulate, and precuneus).
Results: No statistically significant differences were observed in the mean ages of the T2DM group (63.03 ± 10.82) and the normal group (mean age 62.86 ± 10.64).The mean BMI and vfat distributions were 29.84 kg/m2 and 4835.38 ml in the T2DM group as compared to 29.80 kg/m2 and 4831.20 ml in the non diabetic group. T2DM was associated with lower total brain volume (p = 0.024) and white matter volume (p = 0.007). There were no statistically significant reductions in gray matter (p = 0.062) or hippocampal volume (p = 0.290) within the T2DM group. T2DM-related white matter loss was most pronounced in the occipital lobe (p = 0.034). Interestingly, T2DM has shown to be a risk factor for Lewy body and Parkinson’s disease dementia, which has been associated with an abnormal appearance of the occipito-parietal region on brain MRIs. While lower volumes were also observed in the frontal lobe (p = 0.066), left caudate (p = 0.059) and right caudate (p = 0.069) regions, the results did not reach statistical significance.
Conclusion: Lower total brain and white matter volumes suggest a structural impact of the metabolic disorder on the brain. These findings suggest a direct association between T2DM and brain morphology, suggesting potential pathways through which T2DM may contribute to neurological changes.
Clinical Relevance Statement: This study uncovers a significant link between T2DM and reduced brain volume, particularly in white matter, independent of obesity. These findings emphasize the structural impact of diabetes on the brain, which may explain the cognitive decline seen in T2DM patients.
Figure 1: Boxplots of (A) Total brain, gray matter and white matter volumes (B) Temporal, Frontal, Parietal and Occipital lobes (C) Hippocampus, Putamen and Caudate, in T2DM and non-T2DM groups. The MR image shows an example of visceral fat and brain segmentations.
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