Interaction between oral estrogen plus progestogen therapy and ABO blood groups on coagulation activation in postmenopausal women.

OBJECTIVE: The aim of this study was to investigate the effect of postmenopausal hormone therapy on coagulation and whether this effect differs according to ABO blood groups. METHODS: This was a prospective observational study to evaluate factor VIII (FVIII) activity, factor von Willebrand (vWF), and D-dimer (D-Di) levels and ABO blood groups in 61 postmenopausal women using oral estrogen plus progestogen therapy (EPT; 2 mg estradiol + 1 mg norethisterone acetate) for 3 months and in 101 women not using EPT. After 3 months, all eligible women who had completed the treatment scheme proposed for the EPT group or those who opted to participate but had not undergone EPT had a blood sample collected for analysis. RESULTS: Significant differences were observed in FVIII activity and vWF levels in the control group between those carrying group O and non-group O blood. For EPT users, significant differences were observed for FVIII activity, vWF, and D-Di levels. After a multivariate regression analysis, FVIII activity and ABO blood groups were independently associated with vWF levels, whereas interaction between ABO blood groups and EPT were independently associated with FVIII activity. Besides diabetes, the ABO × EPT interaction was also noted to be independently associated with D-Di levels. CONCLUSIONS: These findings suggest an interactive effect between oral EPT and non-O blood groups, contributing to the mechanism by which estrogen triggers the hypercoagulability state and increased risk for venous thrombosis in women undergoing oral EPT.

Assessment of hypercoagulability markers and lipid levels in postmenopausal women undergoing either oral or transdermal hormone replacement therapy.

BACKGROUND: This study investigated the effect of either oral or transdermal hormone replacement therapy (HRT) on haemostatic, fibrinolytic and lipid profiles in a group of Brazilian women 3 months after beginning treatment by comparing these results with those obtained immediately before HRT. METHODS: Plasma levels of TAT, DDi, F1+2, PC, PS, AT, PAI-1 and serum lipids were determined in blood samples collected from 24 women undergoing oral HRT and from 11 women undergoing transdermal HRT. RESULTS: Significant increases in DDi and F1+2 plasma levels were observed after 3 months of oral HRT, while PS levels decreased. After transdermal HRT, a significant decrease was observed only for AT levels. CONCLUSION: After 3 months of oral HRT and in the absence of major genetic and acquired risk factors, women displayed a predisposition for activation of blood coagulation, and an increased activity of the fibrinolytic system. Oral HRT seemed to be more effective in predisposing haemostatic changes as compared to transdermal.

Effect of oral hormone replacement therapy on plasma homocysteine levels.

BACKGROUND: Various inherited or acquired conditions can lead to mild or severe hyperhomocysteinemia, which has toxic effects on the vascular endothelium. It has been reported that hormone replacement therapy is associated with decreased homocysteine plasma levels, but this is still a controversial issue. PURPOSE: To compare homocysteine plasma levels in women before and after 3 months of oral hormone replacement therapy. METHODS: Twenty-four women were selected to take part in the study. Blood samples were collected immediately before hormone replacement therapy (cyclic association of 2 mg of estradiol valerate and 1 mg of cyproterone acetate) and three months after the beginning of hormone replacement therapy. Samples collected before hormone replacement therapy were used as controls. Plasma homocysteine levels and the presence of C677T mutation in the methylene tetrahydrofolate reductase gene were evaluated in all participants. RESULTS: The methylene tetrahydrofolate reductase gene mutation was detected in 8 women (33.3%) in heterozygosis, in 3 (12.5%) in homozygosis, and 13 women (54.2%) did not present the mutation. No significant differences were observed in homocysteine levels before and after three months of oral hormone replacement therapy, regardless of the C677T genotype. CONCLUSIONS: The results obtained indicate that homocysteine plasma levels are not affected after three months of oral hormone replacement therapy.