Relationship between zinc-related nutritional status and the progression of multiple sclerosis

Abstract

BackgroundMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. ObjectiveTo investigate plasma and erythrocyte zinc status and its relationship to MS. MethodsCross-sectional study, including 98 participants, distributed in groups: case (MS, n = 49), diagnosed with MS and control (n = 49), matched by age and sex with the case group. Zinc was analyzed by flame atomic absorption spectrophotometry, and superoxide dismutase (SOD) activity by spectrophotometry. ResultsMean plasma zinc was 94.6 (22.1) μg/dL for MS patients and 81.5 (31.3) μg/dL for control group, with statistical difference (p = 0.023). The mean erythrocyte zinc was 83.6 (41.6) µg/gHb for case group and 72.6 (31.5) µg/gHb for control. Erythrocyte SOD activity was above reference values, significantly different for MS patients (p = 0.003). There was a significant direct correlation between erythrocyte zinc and SOD (r = 0.835; p < 0.001). SOD showed inverse correlation with MS outbreaks (r = -0.317; p = 0.027). ConclusionPatients with MS have normal plasma and elevated erythrocyte zinc. Erythrocyte zinc showed positive correlation with SOD, which correlated inversely to outbreaks.