Plasma homocysteine concentration related to diet, endothelial function and mononuclear cell gene expression among male hyperlipidaemic smokers

Background Elevated plasma concentration of homocysteine is an independent risk factor for development of cardiovascular diseases. Materials and methods We evaluated potential links between homocysteine and atherothrombogenesis by relating the plasma concentration of homocysteine to (i) dietary antioxidants and omega-3 fatty acids land determined influen ce of intervention with antioxidants or omega-3 fatty acids); (ii) markers of endothelial cell function; and (iii) peripheral blood mononuclear cell m RNA levels. Results We observed an inverse relationship between the plasma homocysteine concentration and dietary intake of vegetables, vitamin C and beta-caroten e and between homocysteine and the serum concentration of folate. vitamin B -12 and omega-3 fatty acids. Intervention with antioxidants or omega-3 fatt y acids did not affect plasma homocysteine concentration. The plasma levels of cysteinylglycine and vitamin B-12 correlated positively with circulatin g E-selectin and VCAM-1. respectively, whereas folate in serum and blood co rrelated negatively with P-selectin. A negative correlation was found betwe en the concentrations of homocysteine and von Willebrand factor. Negative a nd positive correlations were found between plasma homocysteine and the mon onuclear cell mRNA levels of peroxisome proliferator activated receptor del ta (PPAR delta) and c-myc respectively. A negative correlation was also fou nd between plasma homocysteine and mononuclear cell mRNA levels of the prot eoglycan serglycin. Homocysteine was not correlated with serum activity of glutathione peroxidase or with the mRNA level of glutathione peroxidase in mononuclear cells. Conclusion The plasma homocysteine level was negatively correlated with die tary intake of vegetables, including vitamins C and E, and serum omega-3 fa tty acids, whereas supplementation with antioxidants or omega-3 fatty acids did not affect plasma homocysteine concentration. Homocysteine was not ass ociated with circulating adhesion molecules or increased procoagulant activ ity, but homocysteine may alter mononuclear cell gene expression. Cysteine showed no significant correlation with these parameters.