Exploring oxidative stress biomarkers in neurocognitive disorders: association between superoxide dismutase and cognitive function

Abstract

Superoxide dismutase (SOD) is an endogenous antioxidant enzyme essential for maintaining oxidative balance in our body. Cognitive problems, both neurodegenerative and vascular, have been linked to alterations in inflammatory and oxidative stress conditions. The aim of this study was to analyze the relationship between SOD values and cognitive function.

A prospective observational cross-sectional study was carried out with patients presenting for consultation due to cognitive symptoms. For screening, the Montreal Cognitive Assessment (MoCA) was used, broken down into the following domains: visuospatial function (VS), language (L), identification (I), abstraction (Ab), orientation (O), attention (At) and memory (M). SOD was quantified in red blood cell lysate by spectrophotometry and expressed in U/mL. A simple linear regression model was used for the biomarkers, considering them as a dependent variable and all other variables as independent prognostic factors, with a significance level set at p<0.05 for all cases.

Seventy-six patients were included in the study with a mean age of 68.39 ± 11.86 years, female sex predominating,  with a mean years of schooling of 08.13± 04.40. The mean MoCA test score was below the cut-off point (22.36 ± 06.30). Linear regression analysis revealed a negative association between MoCA total score (p= 0.0008), as well as for domains VS (p = 0.0142) and L (p = 0.2610). However, for domains I (p= 0.4639), At (p=0.0448), Ab (0.0233), M (0.9104) and O (p = 0.6965), no significant associations were found.

The significant but diverse association between VS vs At and Ab domain could demonstrate the differential role of SOD in different brain areas, especially in the prefrontal cortex. These results support the relationship between oxidative stress and brain pathologies that has been documented in recent years.