Influence of Cardiorespiratory Fitness and MRI Measures of Neuroinflammation on Hippocampal Volume in Multiple Sclerosis Patients (S27.007)

Abstract

<h3>Objective:</h3> To investigate whether higher cardiorespiratory fitness (CRF) may limit the detrimental effects of neuroinflammation on hippocampal volume in the main multiple sclerosis (MS) clinical phenotypes. <h3>Background:</h3> The hippocampus is a clinically-relevant brain region that is characterized by neuroplasticity and neurogenesis also in adults. Neuroinflammation and CRF may specifically influence hippocampal integrity, thus modulating the processes promoting neurogenesis and neuroprotection that contribute to the preservation of functions. <h3>Design/Methods:</h3> Brain structural MRI scans and maximum oxygen consumption (VO₂max), a proxy of CRF, were acquired from 81 MS patients (27 relapsing-remitting [RR] and 54 progressive [P]), and 47 age- and sex-matched healthy controls (HC). White matter T2-hyperintense lesion volume (T2-LV) and choroid plexus volume (CPV) were quantified as neuroinflammatory measures. Associations of T2-LV, CPV and CRF with normalized brain (NBV), gray matter (NGMV), thalamic (NTV) and hippocampal volumes were assessed using linear regression analysis. Stepwise hierarchical regression models were used to evaluate the independent contribution of demographic, clinical, T2-LV, CPV and VO₂max in explaining the aforementioned volumes. <h3>Results:</h3> In MS, higher T2-LV was significantly associated with lower global and regional brain volumes (standardized-β from −0.706 to −0.356, p≤0.009), except for NGMV (p=0.105). Higher CPV was significantly associated only with lower NBV and NTV in both RRMS and PMS patients (standardized-β from −0.545 to −0.290, p≤0.045). Higher VO₂max was significantly associated only with higher normalized hippocampal volume only in RRMS patients (standardized-β=0.448, p=0.013). Using stepwise hierarchical regression models, T2-LV in both RRMS (ΔR²=0.124, p=0.043) and PMS patients (ΔR²=0.095, p=0.028) and VO₂max only in RRMS patients (ΔR²=0.153, p=0.014) were found to explain a significant portion of hippocampal volume variance. <h3>Conclusions:</h3> By exerting beneficial neurotrophic effects, a higher CRF may have a specific neuroprotective role for the hippocampus, mainly in the early phases of MS. <b>Disclosure:</b> Mr. Morozumi has nothing to disclose. Mr. Preziosa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bristol Myers Squibb . Mr. Preziosa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Sanofi Genzyme. Mr. Preziosa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Novartis. Mr. Preziosa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Roche. Mr. Preziosa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Merck. Dr. Albergoni has nothing to disclose. Monica Margoni has received research support from MAGNIMS. Elisabetta Pagani has nothing to disclose. Alessandro Meani has nothing to disclose. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda, and Teva Pharmaceutical Industries. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda, and Teva Pharmaceutical Industries. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Nature. The institution of Dr. Filippi has received research support from Biogen Idec, Merck-Serono, Novartis, Roche, Teva Pharmaceutical Industries, Italian Ministry of Health, Fondazione Italiana Sclerosi Multipla, and ARiSLA (Fondazione Italiana di Ricerca per la SLA). Maria Assunta Rocca has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bayer, Biogen, Bristol Myers Squibb, Celgene, Genzyme, Merck Serono, Novartis, Roche, and Teva. The institution of Maria Assunta Rocca has received research support from Italian Ministry of Health, MS Society of Canada and Fondazione Italiana Sclerosi Multipla.