Background and purpose: Diabetes type 2 (DM2) is associated with accelerated cognitive decline and structural brain abnormalities. Macrovascular disease has been described as a determinant for brain MRI changes in DM2, but little is known about the involvement of other DM2-related factors.
Methods: Brain MRI was performed in 1043 participants (151 DM2) with symptomatic arterial disease. Brain volumes were obtained through automated segmentation.
Results: Patients with arterial disease and DM2 had more global and subcortical brain atrophy (-1.20% brain/intracranial volume [95%CI -1.58 to -0.82], P<0.0005 and 0.20% ventricular/intracranial volume [0.05 to 0.34], P<0.01), larger WMH volumes (0.22 logtransformed volume [0.07 to 0.38], P<0.005), and more lacunar infarcts (OR 1.75 [1.13 to 2.69], P<0.01) than identical patients without DM2. In patients with DM2, high glucose levels (B-0.12% per mmol/L [-0.23 to -0.01], P<0.05) and diabetes duration (B-0.05% per year [-0.10 to -0.001], P<0.05) were associated with global brain atrophy.
Conclusions: In patients with symptomatic arterial disease, DM2 has an added detrimental effect on the brain. In patients with DM2, hyperglycemia and diabetes duration contribute to brain atrophy.