Abstract
BACKGROUND: Coronary artery disease (CAD) cannot be sufficiently explained by the presence of traditional risk factors. Cathepsin D has been proposed to serve as a surrogate marker of atherosclerosis but its alterations in CAD patients have not been studied. OBJECTIVE: To evaluate serum cathepsin D concentrations in relation to the presence and severity of CAD. MATERIALS AND METHODS: A total of 104 subjects were recruited; 71 patients with suspected CAD and 33 healthy subjects. Thirty-four patients had >50% coronary stenosis of at least one artery (CAD+); the remaining 37 patients had <50% stenosis (CAD-) based on angiography. CAD+ patients were sub-divided into three sub-groups with single (SVD; n=15), double (2VD; n=9), and triple vessel (3VD; n=10) disease. Serum soluble cathepsin D concentrations were determined using an enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum cathepsin D concentrations were significantly higher in the CAD+ compared with healthy control (p=0.016) but not CAD- group (p=0.098). Within the CAD+ group, patients with 3VD had significantly higher serum cathepsin D concentrations compared with the SVD group (p=0.025), and also compared with the CAD- (p=0.011) and SVD (p=0.001) groups. No significant associations were found between serum cathepsin D concentrations and potential confounders including age, sex, blood pressure, smoking history and dyslipidemia. CONCLUSION: Serum cathepsin D concentrations may be associated with the presence of CAD.