INS and diabetes mellitus: Chronic hyperglycemia, repeated hypoglycemic episodes, vascular disease, and possibly the direct effects of insulin on the brain may all be implicated.[25–27] Vascular impairment induced by diabetes mellitus could play an important role in the etiology of brain atrophy.[28–30] Blood glucose levels were also proven to be associated with cortical thinning.[31,32] The dysregulation of glycemic variability caused by T2DM may also contribute to brain atrophy.[33]