Relative value of plasma copper, zinc, lipids and lipoproteins as markers for coronary artery disease

Studies in experimental animals have suggested an association between dietary copper deficiency, alone or with an attendant elevated intake of zinc, and an increase in serum total cholesterol. These findings led some to theorize that a dietary imbalance of zinc and copper may be a factor in the etiology of coronary heart disease. Plasma zinc and copper levels were measured in 60 adult male patients with confirmed coronary artery disease and compared with serum levels of lipids and lipoproteins in the same patients. The results were compared to the accepted values in normal adult males. In subjects with significant coronary artery atherosclerosis (≧ 50% luminal occlusion) there was no correlation between plasma zinc or copper with serum lipids or lipoproteins. However, total cholesterol was significantly correlated with low density lipoprotein (LDL) cholesterol, triglycerides, and inversely correlated with HDL-C : T-Chol ratio. Although dietary zinc and/or copper may influence the plasma levels of these trace metals, our studies show that there was no association between plasma zinc or copper and the serum levels of lipids or lipoproteins; we believe that this indicates that these trace metals are of doubtful value as markers for coronary atherosclerosis.