In newly diagnosed diabetes, hyperglycemia is associated with increased brain iron deposition, measured by MRI-based Quantitative Susceptibility Mapping (QSM)

Long-term Type 2 diabetes mellitus (T2DM) affects multiple organs and systems throughout the body, including the cardiovascular, renal, and nervous systems. In the brain, T2DM impacts brain function, leading to cognitive impairment. Due to the faster progression of cognitive decline in diabetic patients, we aim to investigate the relationship between newly diagnosed T2DM and iron deposition by brain MRI technique. We used Quantitative Susceptibility Mapping (QSM), an advanced brain MRI technique, to non-invasively quantify iron deposition in the brain of elderly patients and healthy control subjects. In all patients, blood glucose and iron levels and their correlates parameters were evaluated. QSM revealed increased iron deposition in the putamen of elderly diabetic patients although newly diagnosed compared to healthy controls. QSM significantly correlated with high blood glucose levels and insulin resistance, but not with blood iron levels. Results suggest that increased iron deposition in the putamen, as analyzed by QSM, is worsened by hyperglycemia and insulin resistance, already when diabetes is newly diagnosed. Addressing this issue could improve on the one clinical inertia towards diabetes hand newly diagnosed, with an improvement in diabetes management strategies itself, and on the other hand, it could focus attention on increased putamen iron deposition as a predictive indicator of neurocognitive impairment in T2DM.