High plasma levels of CD40 are associated with low coenzyme Q and vitamin E content of low‐density lipoprotein in healthy men

Abstract

Objective. There is a growing body of evidence to suggest that low‐density lipoprotein (LDL) cholesterol, inflammation and oxidative stress are pivotal in the development of cardiovascular disease, but their interconnections are not well known. The objective of this study was to determine whether immunological activation, reflected by the plasma levels of soluble CD40 (sCD40), interleukin (IL)‐1β, tumor necrosis factor‐α and IL‐6 are associated with the antioxidant potential of LDL particles or with common lipid, immunological or thrombotic markers in 51 young healthy men. Material and methods. We determined the coenzyme Q level from an oxidized LDL fraction, obtaining the concentration for ubiquinone, which indicates total coenzyme Q levels. Results. The plasma level of sCD40 was negatively correlated with LDL ubiquinone (r = −0.45, p = 0.001) and E vitamin (r = −0.37, p = 0.008) and positively correlated with plasma concentration of plasminogen activator inhibitor‐1 (PAI‐1, r = 0.52, p = 0.002) and caspase‐1 (r = 0.40, p = 0.004). No correlation was detected between sCD40 and plasma lipid or C‐reactive protein concentrations. As sCD40 was strongly correlated with the content of LDL ubiquinone and vitamin E, their values were compared according to groups formed by sCD40 tertiles. Analysis of variance showed that there were significant differences in LDL ubiquinone (p<0.0001) and vitamin E (p = 0.004) concentrations between sCD40 tertiles. Conclusions. The data indicate that increased activation of the CD40 system is related to low levels of LDL ubiquinone and vitamin E. This suggests that chronic or increased immunological activation may consume the antioxidant potential of LDL particles.

• Antioxidants
• atherosclerosis
• CD40
• inflammation

Acknowledgements

The study was funded by medical research grants from the Turku University Central Hospital, the Academy of Finland, Helsinki, the Medical Research Foundation of Tampere University Hospital, the Paavo Nurmi Foundation and the Finnish Foundation for Cardiovascular Research.