Venous Thrombosis and Conjugated Equine Estrogen in Women Without a Uterus

Abstract

Background: Postmenopausal hormone therapy has been associated with a 2-to 3-fold increased risk of venous thromboembolism (VT) (including deep vein thrombosis and pulmonary embolism) in observational studies and secondary prevention clinical trials. Clinical trial data on the effects of estrogen alone on VT are limited.Methods: The Women's Health Initiative estrogen trial enrolled 10 739 women aged 50 to 79 years without a uterus. Participants were randomly assigned to receive conjugated equine estrogen (0.625 mg/d) or placebo.Results: During a mean of 7.1 years, VT occurred in 111 women randomly assigned to receive estrogen (3.0 per 1000 person-years) and 86 randomly assigned to receive placebo (2.2 per 1000 person-years; hazard ratio, 1.32; 95% confidence interval, 0.99-1.75). Deep venous thrombosis was reported in 85 women randomly as-signed to receive estrogen (2.3 per 1000 person-years) and 59 randomly assigned to receive placebo (1.5 per 1000 person-years; hazard ratio, 1.47; 95% confidence interval, 1.06-2.06). The VT risk was highest in the first 2 years. There were no significant interactions between estrogen use and age, body mass index, or most other VT risk factors. Comparison of Women's Health Initiative VT findings for estrogen and previous Women's Health Initiative findings for estrogen plus progestin showed that the hazard ratios for estrogen plus progestin were significantly higher than those for estrogen alone (P=.03), even after adjusting for VT risk factors. Conclusion: An early increased VT risk is associated with use of estrogen, especially within the first 2 years, but this risk increase is less than that for estrogen plus progestin.

Hormone Therapy and Risk of Venous Thromboembolism Among Postmenopausal Women in Taiwan – A 10-Year Nationwide Population-Based Study –

“…2, 19 Data from epidemiologic and randomized controlled studies consistently demonstrates an increased risk of VTE events in postmenopausal women who use oral HT. 2,7,14, 19 In the HERS trial, VTE was not confined to the first year of oral HT use, but the increased risk declined from approximately 4-fold in the first year to less than 2-fold after the third year of use. 20 The WHI studies confirmed the magnitude and timing of the VTE risk estimates from previous studies.…”

Progress in Mining the Human Proteome for Disease Applications

“…In some studies, the observed effects were similar for the two preparations for some outcomes, including stroke WassertheilSmoller et al, 2003) and hip fracture (Cauley et al, 2003;Jackson et al, 2006), whereas E þ P effects were unfavorable compared to those for E-alone for other outcomes, including coronary heart disease (CHD) (Hsia et al, 2006;Manson et al, 2003), breast cancer (Chlebowski et al, 2003;Stefanick et al, 2006), and venous thromboembolism (VT) (Curb et al, 2006;Cushman et al, 2004). The spectrum of biological changes induced by hormone therapy in relation to the outcome effects has remained unclear.…”

Hormonalna terapia zastępcza – czy droga podania ma znaczenie?

“…Pojawiały się jednak analizy, które niezależnie od badania WHI (Women's Health Initiative) wskazywały, że ryzyko rozwoju ŻChZZ wzrasta w grupie kobiet, u których dodawane są progestageny w porównaniu z grupą stosującą same estrogeny [17,18].…”