Correlation between plasma total homocysteine and copper in patients with peripheral vascular disease

Increased concentrations of both plasma total homocysteine and copper are separately associated with cardiovascular disease. Correlations between plasma total homocysteine, trace elements, and vitamins in patients with peripheral vascular disease have not been investigated.

The concentrations of trace elements in plasma were determined by the multielement analytical technique of total-reflection x-ray fluorescence spectrometry. Plasma total homocysteine was determined by HPLC.

In the univariate and multivariate regression analyses, copper was positively correlated with plasma total homocysteine in all subjects (coefficient +/- SE, 0.347 +/- 0.113; P = 0.0026 and coefficient +/- SE, 0.422 +/- 0.108; P = 0.0002, respectively), and in patients with peripheral vascular disease (coefficient +/- SE, 0.370 +/- 0.150; P = 0.016; and coefficient +/- SE, 0.490 +/- 0.151; P = 0.0025, respectively). Correlation between copper and plasma total homocysteine was not detected in healthy control subjects. The concentration of calcium in plasma (67.5 vs 80. 8 microg/g) was significantly lower in the patients than in the control subjects (P = 0.02). When the patients were divided into groups, the patients with suprainguinal lesions had significantly higher copper concentrations (P = 0.04) and significantly lower selenium and calcium concentrations (P = 0.01 and 0.008, respectively) than the healthy subjects. Patients had higher concentrations of autoantibodies against oxidized LDL and concentrations of thiobarbituric acid-reactive substance than the healthy subjects (P <0.0001 and P = 0.001, respectively). The concentrations of plasma total homocysteine and alpha-tocopherol were significantly higher, and the concentrations of vitamin B(6) and beta-carotene were lower in the patients than the healthy subjects.

Our findings suggest that the atherogenicity of homocysteine may be related to copper-dependent interactions.