Assessing the burden of vascular risk factors on brain atrophy in multiple sclerosis: A case- control MRI study

Background: Some studies have indicated the importance of considering the presence of vascular comorbidities as negative prognostic factors for MRI outcomes in multiple sclerosis (MS). This study aimed to evaluate the possible influence of the most frequent vascular risk factors on brain volume in MS, also exploring the burden of their combined effects. Methods: MS patients with at least one vascular risk factor and a control group of MS patients were enrolled. Patients underwent brain MRI and the volumes of the whole brain (WB), white matter (WM), grey matter (GM), and cortical GM were estimated by SIENAX. Longitudinal atrophy was assessed by SIENA. Results: The sample included 326 MS patients, of these 49 (15%) had diabetes mellitus, 44 (13.4%) hypertension and 50 (15.3%) were active smokers. Multiple regression analyses revealed that diabetes mellitus was associated with significant reductions in WB (p = 0.03), GM and cortical GM (p = 0.01) volumes. Similarly, reduced cortical GM volume was associated with hypertension (p < 0.05). A strong relationship between the co-occurrence of multiple vascular risk factors and lower cortical GM volume (p = 0.007) was also identified. Ninety patients were included in the longitudinal study and a greater annualized brain volume loss was found in those with at least one vascular risk factor than in the control group (−1.05% vs. −0.58%, p = 0.005). Conclusions: Our results show that the vascular comorbidities affect brain atrophy, indicating that these conditions should be carefully monitored in patients with MS with a focus on limiting brain damage.