title: Plasma extracellular superoxide dismutase levels in an Australian population with coronary artery disease.
abstract: In vitro experiments suggest that free radicals may contribute importantly to atherogenesis. Superoxide dismutase (SOD), particularly extracellular SOD (EC-SOD), which accounts for the majority of SOD biological activity, is a major superoxide scavenger. We explored factors that may affect plasma EC-SOD levels measured by ELISA and assessed the association between plasma EC-SOD and coronary artery disease documented angiographically in 590 white Australian patients </=65 years old. Mean+/-SEM plasma EC-SOD in female patients (113.6+/-13.2 ng/mL) was significantly higher than in male patients (86.6+/-5.1 ng/mL, P<0.0001), and all 19 patients with levels >400 ng/mL were heterozygous for the Arg213-->Gly mutation at the EC-SOD gene; there was also a positive correlation with age (r=0.131, P=0.0016). Plasma EC-SOD in current smokers (75. 0+/-9.3 ng/mL) was much lower than in nonsmokers (111.7+/-8.2 ng/mL, P<0.01), and ex-smokers had intermediate levels (84.3+/-7.1 ng/mL). Levels were significantly lower in patients with than in those without a history of acute myocardial infarction (MI) (76.1+/-7.5 versus 110.1+/-6.0 ng/mL, P<0.05), and low plasma EC-SOD was independently associated with an increased likelihood of a history of MI (OR, 2.04; 95% CI, 1.10 to 3.82); higher EC-SOD levels also tended to be associated with delayed onset of MI. In conclusion, our study establishes that in patients assessed by coronary angiography, circulating EC-SOD is lower in men than in women and in smokers of each sex and that low levels are independently associated with a history of MI. These findings are consistent with EC-SOD's being protective and contributing to reduced coronary risk.
authors.affiliation: Department of Cardiovascular Medicine, University of New South Wales, Prince Henry/Prince of Wales Hospitals, Sydney, Australia. x.l.wang@unsw.edu.au
authors.forename: X L
authors.initials: XL
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Adachi
authors.forename: A S
authors.initials: AS
authors.lastname: Sim
authors.forename: D E
authors.initials: DE
authors.lastname: Wilcken
mesh_terms: D000367:Age Factors; D001315:Australia; D003327:Coronary Disease / Q000201:enzymology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020125:Mutation, Missense; D012737:Sex Factors; D012907:Smoking / Q000378:metabolism; D013482:Superoxide Dismutase / Q000097:blood*
chemical_list: D013482:Superoxide Dismutase