title: Erythrocyte zinc, copper, and copper/zinc superoxide dismutase and risk of sporadic amyotrophic lateral sclerosis: a population-based case-control study.
abstract: We investigated through a population-based case-control study the hypothesis that disturbances in the chemistry of copper and zinc and in activity of the antioxidant enzyme copper/zinc superoxide-dismutase (SOD1) are involved in the etiopathogenesis of sporadic amyotrophic lateral sclerosis (ALS). We recruited 20 patients with sporadic ALS and 22 population controls from three northern Italian provinces, and we analyzed zinc and copper content and SOD1 activity in erythrocytes. These variables were unrelated to disease progression as evaluated through a disability score; zinc concentrations inversely correlated with copper in referents but not in patients. SOD1 activity was lower and erythrocyte zinc and copper levels were slightly higher in patients than in referents. Comparing the second to the bottom tertile of erythrocyte SOD1 activity, relative risk of ALS was 0.4 (95% confidence interval 0.1-2.0); the risk further decreased to 0.1 (95% confidence interval 0-0.9) for comparison of highest to lowest tertile (P for trend 0.027). Copper and zinc levels were not associated with disease risk. Our findings indicate that a lower SOD1 activity is associated with ALS, but we cannot be sure whether this association is a marker of causal action or is secondary to a confounder, or to disease onset itself.
authors.affiliation: Department of Hygiene, Microbiology and Biostatistics, University of Modena and Reggio Emilia, Modena, Italy. vinceti@unimo.it
authors.forename: Marco
authors.initials: M
authors.lastname: Vinceti
authors.forename: Margherita
authors.initials: M
authors.lastname: Bergomi
authors.forename: Grazia
authors.initials: G
authors.lastname: Nacci
authors.forename: Vladimiro
authors.initials: V
authors.lastname: Pietrini
authors.forename: Angela
authors.initials: A
authors.lastname: Ferrari
authors.forename: Katia
authors.initials: K
authors.lastname: Fortini
authors.forename: Donata
authors.initials: D
authors.lastname: Guidetti
authors.forename: Patrizia
authors.initials: P
authors.lastname: Sola
authors.forename: Enrico
authors.initials: E
authors.lastname: Rocchi
authors.forename: Domenico
authors.initials: D
authors.lastname: Mancia
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Vivoli
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D016022:Case-Control Studies; D018672:Community Health Planning; D003300:Copper / Q000378:metabolism*; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D012306:Risk; D013223:Statistics as Topic; D013482:Superoxide Dismutase / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc