Magnesium and trace metals: Risk factors for coronary heart disease? Associations between blood levels and angiographic findings

Abstract

A deficiency or an excessive intake of metals with cardiovascular effects is suspected to be involved in the pathogenesis of coronary heart disease (CHD) and sudden death. Therefore, in 106 patients undegoing coronary arteriography, serum levels of six essential metals (magnesium, chromium, copper, manganese, selenium and zinc) and whole blood concentrations of two elements without known essential function (cadmium and lead) were measured using atomic absorption spectrophotometry, including the flameless technique, or neutron activation analysis. The patients were classified into three groups according to severity of CHD as assessed by coronary angiography: those without coronary lesions (n = 31) and those with moderate (n =34) or severe CHD (n = 41). Patients with severe CHD had lower mean serum magnesium and higher serum copper and manganese levels than those without CHD (magnesium, 1.63 ± 0.16 [SD] vs 1.78 ± 0.16 mEg/l, p<0.005; copper, 1.39 ± 0.22 vs 1.24 ± 0.24 mg/l, p<0.05; manganese, 1.30 ± 0.43 vs 1.05 ± 0.40 μg/l, P<0.05). In contrast, metal concentrations in patients with moderate CHD did not differ significantly from control values. There was no significant association between prevalence and severity of CHD and the other elements investigated. Analysis of associations between metal concentrations and clinical characteristics revealed markedly elevated blood cadmium levels in cigarette smokers compared with nonsmokers (2.49 ± 1.72 [n = 28] vs 0.43 ± 0.22 μg/l [n = 18], p<0.001). A correlation was noted between cadmium levels and the number of cigarettes smoked per day (r = 0.725, p<0.001). Our results suggest that a deficiency of magnesium but not of the other metals studied may be present in patients with severe CHD; elevated serum copper and manganese levels do not play a role in the development of CHD in the sample of patients studied; and cigarette smoking may be associated with increased serum cadmium levels, which may explain in part the contribution of smoking to the risk of sudden death in patients with CHD.