A novel morphometric signature of brain alterations in type 2 diabetes: patterns of changed cortical gyrification

Abstract Type 2 diabetes is a chronic disease that creates atrophic signatures in the brain, including decreases of total and regional volume of grey matter, white matter, and cortical thickness. However, there is a lack of studies assessing cortical gyrification in type 2 diabetes. Changes in this emerging feature has been associated mainly with genetic legacy, but environmental factors may also play a role. Here, we investigated alterations of the gyrification index and classical morphometric measures in type 2 diabetes, a disease with complex etiology with both underlying genetic and more preponderant environmental factors. In this cross-sectional study we analyzed brain anatomical magnetic resonance images of 86 participants with type 2 diabetes and 40 healthy control participants, to investigate structural alterations in type 2 diabetes, including whole-brain volumetric measures, local alterations of grey matter volume, cortical thickness and the gyrification index. We found concordant significant decrements in total and regional grey matter volume, and cortical thickness. Surprisingly, the cortical gyrification index was found to be mainly increased in cortical sensory areas in type 2 diabetes. Moreover, it correlated with features of metabolic control. Our findings challenge the classical neurodevelopmental association of gyrification mostly with genetic determinants. While we found mainly increased gyrification in more genetically constrained sensory areas in type 2 diabetes, our correlation results concurrently suggest an influence of metabolic control in alterations of gyrification in type 2 diabetes. Further studies should address causal influences of genetic and/or environmental factors in patterns of cortical gyrification in type 2 diabetes.