Courtesy of Dr Simon Cox and Dr Donald Lyall, this image shows associations between vertex-wise cortical volume measurements from brain MRI and an aggregate vascular risk factor (VRF) measure, from a sample of more than 7,900 participants in the UK Biobank study. The t-map (left) illustrates modest but widespread significant associations between higher aggregate vascular risk and lower cortical volume, especially in anterior lateral and medial temporal lobes. The FDR-corrected q-map (right) indicates relative sparing of dorsal motor/somatosensory and posterior cortical regions.
Additional analyses found significant associations between higher aggregate VRF and lower volumes in subcortical brain structures (accumbens, caudate, hippocampus, pallidum, putamen, thalamus), and between higher aggregate VRF and poorer white matter microstructure in association and thalamic pathways. There was no evidence that any associations differed across the sampled age range (44-79 years). The aggregate VRF measure captured overall vascular risk per individual by counting instances of a self-reported diagnosis of hypertension, diabetes, or hypercholesterolaemia, having ever smoked, having a BMI >25, and having a high waist-hip ratio (>0.85 for females and >0.90 for males). Such factors are known to increase risk for cerebrovascular disease and dementia, although the complex interplay between vascular and cerebral ageing is not yet well understood. Results from these analyses demonstrate small but significant associations between greater vascular risk and poorer brain health in cortical, subcortical, and white matter MRI measures, in a relatively healthy sample of adults in middle and older age.
The image is taken from a recent study published in European Heart Journal:
Cox SR, Lyall DM, Ritchie SJ, Bastin ME, …, Deary IJ. Associations between vascular risk factors and brain MRI indices in UK Biobank. Eur Heart J 2019; 40(28):2290-2300.