Superoxide dismutase is associated with cerebral small vessel disease burden and vascular mild cognitive impairment in elderly patients

Objective To examine the associations between superoxide dismutase (SOD) levels and the burden of cerebral small vessel disease (CSVD), as well as vascular mild cognitive impairment (VaMCI), in elderly patients. Methods In this study, a cohort of 286 elderly individuals was included. Each participant received a comprehensive cognitive assessment. Plasma SOD levels were evaluated. The cumulative CSVD burden was quantified using an ordinal scale ranging from 0 to 4, based on four key imaging indicators of CSVD: white matter hyperintensity, deep cerebral microbleeds, lacunes, and enlarged perivascular spaces in the basal ganglia. To evaluate the associations among SOD levels, CSVD burden, and cognitive function, we employed binary logistic regression analysis, tests for trend, receiver operating characteristic curve analysis, and mediation analysis. Results After adjusting for potential confounders, multivariate logistic regression analysis revealed that elevated levels of SOD were significantly associated with a reduced risk of VaMCI (OR: 0.919; 95% CI: 0.896–0.943; P < 0.001) and a lower likelihood of severe CSVD burden (OR: 0.980; 95% CI: 0.968–0.992; P = 0.001) in elderly patients. Compared with the lowest quartile of SOD levels, the OR for VaMCI in the highest quartile of SOD levels was 0.039 (95% CI: 0.016–0.100; P for trend < 0.001) after adjusting for potential confounders. For severe CSVD burden, the corresponding OR was 0.442 (95% CI: 0.214–0.913; P for trend = 0.011). Mediation analysis revealed that the severe CSVD burden significantly moderated the relationship between SOD levels and VaMCI. Conclusion Elevated SOD levels serve as a protective factor against severe CSVD burden and VaMCI in elderly patients. A portion of the protective effect of increased SOD on VaMCI may be attributed to its role in mitigating the severity of CSVD.