Oxidative stress, depressive symptoms, disability, cognitive outcomes and hand dexterity in relapsing-remitting multiple sclerosis patients with mild/moderate disability

Background This study aimed to comprehensively examine the interplay between demographic factors, peripheral oxidative stress markers, disability, depressive symptoms, cognitive outcomes, and hand dexterity in Relapsing-remitting Multiple sclerosis (RRMS) patients with mild/moderate disability. Methods In this cross-sectional study, RRMS patients with Expanded Disability Status Scale (EDSS)≤3 underwent assessments of cognitive function (Symbol Digit Modalities Test [SDMT], Paced Auditory Serial Addition Test [PASAT-3]), depressive symptoms (Beck Depression Inventory-II [BDI-II]), hand dexterity (Nine-Hole Peg Test [9HPT]), and neurological disability (EDSS). Oxidative stress markers (malondialdehyde [MDA], total antioxidant capacity [TAC], superoxide dismutase [SOD], catalase activity [CAT], glutathione peroxidase [GPx], and reduced glutathione [GSH]) were also measured. Results The studied cohort comprised 83 patients (77.1% females; mean age: 32.65±8.05 years). In addition to negative association between the EDSS and cognitive outcomes in binary logistic regression analysis (SDMT: OR=0.95; p=0.02; PASAT: OR=0.92; p=0.01); neurological disability also correlated with cognitive scores in multivariable linear regression (SDMT: β=−0.23, p=0.047; PASAT: β=−0.36, p=0.002). Education also correlated with the cognitive outcomes (SDMT: β=0.29, p<0.001; PASAT: β=0.27, p=0.01). MDA was associated with abnormal cognitive function (SDMT≤44; OR: 2.98 (95%CI: 1.33, 6.66) but correlation between these outcomes was no longer significant in multivariable linear regression (β=-0.21; p=0.051). Except for a marginal correlation between EDSS and MDA (β=0.21, p=0.04) and between 9HPT-M and TAC (β=0.26, p=0.01), there was no significant finding regarding the correlations between the clinical and laboratory outcomes. Conclusion Even in patients with mild/moderate disability, EDSS and education level were emerged as the strongest predictors of cognitive outcomes in RRMS.