Brain gray matter volume differences in obese youth with type 2 diabetes: a pilot study

Background: Adults with type 2 diabetes (T2D) have significantly lower gray matter volume (GMV) compared to healthy peers. Whether GMV differences exist in youth with T2D remains unclear. Thus, we compared global and regional GMV between obese youth with T2D with age, race and sex similar healthy controls. Methods: In a cross-sectional study, 20 obese youth with T2D underwent T1-weighted brain magnetic resonance imaging (MRI). Comparisons were made to 20 age, race and sex similar controls. Differences in global and regional GMV between groups were identified using voxel-based morphometry (VBM). Results: Youth with T2D had a significantly lower global GMV-to-intracranial volume ratio (0.51 +/- 0.02 in T2D vs. 0.53 +/- 0.02 in controls, p = 0.02, Cohen's d = 0.85). There were 14 regions where GMV was significantly lower in the T2D group, and nine of these were found in either the temporal or occipital lobes. There were six regions with increased GMV in T2D. All regional differences were significant at p < 0.05 after adjusting for multiple comparisons. Conclusions: Results from this pilot study show obese youth with T2D have significantly lower global GMV and regional GMV differences, when compared to their age, race and sex similar peers. Future work is needed to determine whether these brain findings are a direct result of adolescent-onset T2D.