Effects of Semaglutide on Intracranial Blood Flow and Brain-Barrier Permeability in Type-2 Diabetes

A human subjects research study, the primary purpose of which is to assess the EFFECTS OF SEMAGLUTIDE ON INTRACRANIAL BLOOD FLOW AND BLOOD-BRAIN BARRIER PERMEABILITY IN TYPE-2 DIABETES (T2D) through testing of the intervention on patients in a clinical setting. The study will randomize subjects with diabetes to either semaglutide or matching placebo. Magnetic resonance images will be primary endpoint measured at baseline and at one year to assess effect of this FDA approved medication. Given the available evidence supporting the neuroprotective effect of this drug class and stroke reduction with semaglutide, and the investigators preliminary data showing that T2D had significantly reduced total number of distal arterial branches in the brain than non-T2D, the investigators expect treatment with semaglutide will be associated with improved intracranial blood flow condition.

The investigators preliminary data showed that T2D had significantly reduced total number of distal branches as assessed using the investigators quantitative magnetic resonance angiography (MRA) feature measurement method (iCafe) than non-T2D. This reduction represents a decrease in intracranial blood flow condition and can be an indication for ischemia. Clinical trial showed that semaglutide reduces stroke incidence in T2D. The investigators are conducting a randomized, double blind and placebo-controlled study to investigate the biological basis of the observed stroke reduction with semaglutide by demonstrating semaglutide can improve intracranial blood flow condition and reduce bloodbrain barrier (BBB) permeability. The investigators working hypothesis is that it is known that semaglutide has beneficial effects on T2D, therefore, it improves endothelial function for a better cerebral flow condition. However, semaglutide may also improve cerebral flow independently from glucose lowering. Together, the improved cerebral flow condition results in stroke reduction. In order to investigate the independent effects of semaglutide on intracranial blood flow condition and BBB permeability, the investigators will have a designated diabetes care specialist unblinded to the study randomization to carry out glucose management to achieve HbA1C\<7.5% for both treatment groups.