A causal link between youth-onset type 2 diabetes (T2D) and vascular complications is well-established. The brain, as a highly vascular structure, may also be susceptible to the adverse effects of T2D. Brain structural and cognitive differences have been demonstrated in adolescents with T2D, and vascular disease is hypothesized to be a mechanism. We sought to evaluate cerebral blood flow (CBF) in youth with T2D vs. obese, euglycemic controls, and to explore the association between CBF and a non-invasive measure of atherosclerosis, carotid intima medial thickness (IMT). We compared global and regional CBF between 20 youth with T2D (mean T2D duration 2.8 ±2.1 years and mean hemoglobin A1C 7.9 ±2.1%) and 19 age, race, and sex similar obese controls (mean hemoglobin A1C 5.2 ±0.2%), adjusted for socioeconomic status. CBF data were obtained using arterial spin labeling (ASL) MRI. We compared mean CBF values, voxel-wise and globally averaged, between groups using two-sample t-tests. Voxel-wise results were evaluated for statistical significance (p<0.05) after adjustment for multiple comparisons. Carotid IMT in the T2D group was measured using ultrasound and correlated with CBF, both globally and voxel-wise. Compared to obese controls, the T2D group had significantly lower global CBF (49.7 ± 7.2 vs. 63.8 ±11.5 mL/gm/min, p<0.01). There were seven voxel clusters with ≥100 voxels identified with significantly lower CBF in the T2D group, and no clusters with higher CBF. In the T2D group, IMT of the common carotid artery was inversely correlated with CBF, both globally (r= -0.7, p<0.01) and in regional voxel clusters. Global and regional cerebral blood flow is lower in youth with T2D compared to obese controls. Further work is needed to determine whether these CBF findings are related to brain structural or cognitive differences previously reported in youth-onset T2D. The association found between carotid IMT and CBF suggests this may represent a practical way to track CBF in youth with T2D.
J.M. Redel: None. M.W. DiFrancesco: None. G.R. Lee: None. L.M. Dolan: None. A.S. Shah: None.
Cincinnati Diabetes and Obesity Center Pilot Grant Program; Endocrine Fellows Foundation; National Institute of Environmental Health Sciences (ES010957-16); Cincinnati Children’s Hospital