26 September 2002
Objective: The objective was to evaluate the effect of hormone replacement therapy (HRT) on plasma homocysteine levels in postmenopausal women with coronary artery disease (CAD) and to investigate associations of homocysteine to other cardiovascular risk factors. Methods: The women in this single-center, controlled, and randomized study were examined at baseline, and after 3 and 12 months, after they had been recruited consecutively from patients referred for investigational coronary angiography. All analyses were performed examiner blind. They were randomized to HRT consisting of transdermal application of continuous 17β-estradiol with cyclic medroxyprogesterone acetate (MPA) tablets for 14 days every 3rd month, or to a control group. Results: After 3 months of unopposed 17β-estradiol, no significant effect on homocysteine was observed compared to the control group. The absolute decrease of 5% in median plasma homocysteine levels after 12-month HRT did not reach statistical significance. Plasma homocysteine seemed slightly higher in women with three- or four-vessel disease, but the difference was not significant. With increasing homocysteine levels, free tissue factor pathway inhibitor (TFPI) antigen increased, whereas E-selectin decreased. In women with diabetes or elevated blood glucose >6.0 mmol/l, plasma homocysteine was correlated to body mass index, C-peptide and insulin as well as age. Conclusion: Transdermal application of 17β-estradiol and sequential MPA do not affect plasma homocysteine in women with established CAD. Plasma homocysteine is stable in women with CAD over time, and unless special intervention is undertaken, repetitive measurements are not necessary in this particular group of high-risk individuals. The circulating anticoagulant TEPI is related to plasma homocysteine.