Background: CD36 is a major macrophage scavenger receptor for oxidised low-density lipoprotein particles. Soluble CD36 (sCD36) is circulating as a ligand-bound complex and may be present in microparticles shed from cells such as platelets, monocytes/macrophages, or adipocytes. Positive association of plasma sCD36 with insulin resistance has been reported, and it has been proposed that sCD36 might represent a marker of macrophage activation and inflammation leading to atherosclerosis. Recently we have identified an association between CD36 polymorphism and low thickness of atheromatous plaque, suggesting its protective effect against atherosclerosis development.

Aim: To obtain insight into the relationship between plasma concentration of sCD36 and radiological parameters of atherosclerosis in patients with early-onset coronary artery disease (CAD).

Methods: The study group comprised 70 clinically stable patients (18 women and 52 men) with early CAD (aged no more than 50 years for men and 55 years for women). Fasting blood sample was taken for serum glucose, lipid profile, ApoA1, ApoB, Lp(a), and plasma sCD36 protein measurements. Each subject’s weight, height, waist and hip circumference, and systolic and diastolic blood pressure were measured, and the body mass index, waist-to-hip ratio, and mean arterial pressure were calculated. Doppler ultrasound examinations of carotid and peripheral arteries were performed in all patients. Thickness of intima–media complex (IMC) of common carotid (CCA) and brachial arteries, as well as density and thickness of atheromatous plaque at CCA bifurcation, were measured with M’Ath programme. Plasma concentrations of CD36 antigen were measured by ELISA. Correlations between quantitative variables and sCD36 plasma concentration were assessed with the Spearman rank correlation coefficient (Rs). Associations between qualitative variables and sCD36 plasma concentration were tested with the Mann-Whitney U test.

Results: We observed no significant correlations between sCD36 concentration and radiological parameters of atherosclerosis. We found only borderline significant negative correlation of sCD36 concentration with thickness of IMC of left brachial artery. We also observed a significantly negative correlation with CCA plaque density, but only in the female subgroup and on the right side. Borderline higher sCD36 plasma concentrations were observed in patients with lower ankle–brachial index value (< 0.9).

Conclusions: The results of the study show no strong associations and do not prove either detrimental or beneficial influence of sCD36 on radiological parameters of atherosclerosis. Further research is necessary to assess the association of high plasma sCD36 concentrations with the risk of plaque instability in patients with early-onset CAD.