Exploring the relationship between lymphatic system damage and insulin resistance in T2DM based on vascular periadventitial tensor analysis and triglyceride-glucose index

Type 2 diabetes mellitus (T2DM) can lead to dysfunction in the brain’s glymphatic system, but the relationship between glymphatic system function and insulin resistance remains unclear. The aim of this study was to investigate the connection between changes in the brain’s glymphatic system function in T2DM and the surrogate marker for insulin resistance, the Triglyceride-Glucose Index (TyG). A total of 28 T2DM patients (T2DM group) and 24 healthy volunteers (HC group) were included in this study. We outlined circular regions with a diameter of 5.0 mm on diffusion tensor imaging (DTI) in the projection and association fibers in the body of the lateral ventricle. We compared the differences in DTI-ALPS index and related fiber diffusivity between the two groups. Additionally, TyG index in T2DM patients was calculated based on fasting blood glucose and triglyceride levels. Age was included as a covariate to analyze the correlation between the ALPS index and TyG index in T2DM patients. The results showed that the ALPS index and Dxproj in the T2DM group were lower than those in the HC group, while Dyproj was higher than in the HC group. In the T2DM group, the ALPS index, Dxassoc, and TyG index were all negatively correlated. The decreased ALPS index and fiber diffusivity in T2DM patients may be associated with the TyG index, suggesting a relationship between insulin resistance, lymphatic system damage, and white matter microstructure.