Homocysteine, B Vitamins and Immune Activation in Coronary Heart Disease

Abstract

Moderate hyperhomocysteinemia is associated with an increased risk of coronary heart disease (CHD). An inverse relationship usually exists between homocysteine and folate concentrations, and folate supplementation is often able to lower homocysteine concentrations. Thus, insufficient dietary intake of folate and/or vitamin B12 is considered to be responsible for the development of hyperhomocysteinemia. Inflammation and immune activation appear also to be important in the pathogenesis of CHD and may influence availability of folate. Blood concentrations of homocysteine, B vitamins and neopterin were examined in 35 patients with CHD verified by coronary angiography, (21 patients with one-artery disease, 9 with two- or three-artery disease, 5 with restenosis). Compared to 30 healthy controls, a significant proportion of patients presented with increased homocysteine concentrations. Hyperhomocysteinemia coincided with lower folate and also with higher neopterin concentrations indicating immune system activation. In addition, correlations existed between neopterin and homocysteine (r = 0.472, p < 0.01) and folate (r = -0.370, p = 0.01). We conclude that higher homocysteine is not only associated with lower circulating folate but also with higher neopterin. Immune activation could be involved to cause an increased demand for folate resulting in hyperhomocysteinemia even when dietary folate intake is within the recommended range.