Body Composition Analysis in Young Patients with Recent Diagnosis of Multiple Sclerosis: An Exploratory Study

Background/Objectives: The relationship between body composition (BC), sarcopenia, and multiple sclerosis (MS) remains poorly understood. A high body mass index (BMI) is associated with a higher risk of MS and brain atrophy. However, limited data are available on BC in patients in the early stages of the disease. This study investigates differences in BC and sarcopenia between early-diagnosed patients with MS (pwMS) and healthy controls (HC), while exploring correlations with brain atrophy and biomarkers of oxidative stress and axonal injury. Methods: This project is part of BPS-ARMS, a cross-sectional study conducted in 2019-2022 at Verona University involving 51 participants aged 18-40 years, diagnosed with MS in the last two years, and currently not taking disease-modifying drugs. Seventeen (69% females) pwMS consented to be enrolled in this sub-study, matched by age and body mass index (BMI) to 17 HC; BC was assessed using Dual-Energy X-ray Absorptiometry (DXA). Collected variables included BMI, fat and lean mass, and sarcopenia index (SI). A brain MRI scan was performed in pwMS between 6 months before and 1 month after inclusion, to assess T2 lesion, normalized brain (NBV), white matter (WMV) and gray matter (GMV) volumes, and presence of gadolinium-enhancing (Gd+) lesions. Biomarker analysis was performed on blood samples collected at baseline. Oxidative stress was assessed as plasma gluthatione (GSH) and gluthatione disulphide (GSSG) levels and STAT1 phosphorylation at Tyr 701 (pSTAT) in peripheral blood cells, while axonal damage was measured as serum neurofilament light chain (NfL) levels. Results: A significantly lower SI was found in pwMS compared to HC (p = 0.038), particularly in female cases. In the pwMS group, WMV was inversely correlated with SI (p = 0.028) and lean body mass (p = 0.016). BMI was inversely correlated with WMV (r = -0.658, p = 0.02). A significant inverse correlation of plasma GSSG level was found with SI (r = -0.546, p = 0.023) and lean mass (r = -0.585, p = 0.014); the ratio of GSH over GSSG (GSH/GSSG) was directly correlated with SI (r = 0.518, p = 0.036) and lean mass (r = 0.568, p = 0.017). Conclusions: Patients with early-stage untreated MS and low-grade disability are more prone to sarcopenia than HC. Moreover, MS subjects with higher BMI show lower brain white matter volume and a lower global brain volume.