The prevalence of blood copper deficiency among patients with ischemic heart disease and its relation to disease severity

Background: Copper is an essential trace element for oxidative stress regulation and lipid metabolism; however, the relationship with ischemic heart disease in humans remains controversial. Objectives: To evaluate the association between serum copper and the angiographic presence and severity of coronary artery disease (CAD). Methods: This study enrolled 628 consecutive patients undergoing coronary angiography. Patients were stratified into four groups: no CAD ( n = 146), nonobstructive CAD (<50% stenosis, n = 66), no CAD with incidental calcification ( n = 95), and obstructive CAD (≥50% stenosis, n = 321). Obstructive CAD patients’ disease severity was assessed and correlated with serum copper level. Results: Serum copper did not differ significantly across CAD categories (medians: 108.7–112.5 µg/dL; P = 0.958). On multivariable analysis, serum copper was not independently associated with CAD presence (adjusted odds ratios [aOR] =1.000/µg/dL, 95% confidence interval [CI]: 0.996–1.004, P = 0.850); diabetes mellitus was the only significant predictor (aOR = 1.389, P = 0.049). Among patients with obstructive CAD, serum copper showed no association with different parameters of disease severity (P > 0.05). No effect modification by diabetes was observed ( P = 0.849). Serum copper demonstrated negligible discriminative ability for CAD presence (area under the receiver operating characteristic curve = 0.506, 95% CI: 0.449–0.562). Conclusion: Serum copper is not independently associated with the presence or severity of CAD after adjustment for established cardiovascular risk factors. These findings do not support routine serum copper measurement as a clinical biomarker for CAD severity assessment. The null finding in our cohort does not negate the biological pathways of copper as an enzymatic cofactor and antioxidant.