Recently, Canonico and colleagues published an analysis from the Women’s Health Initiative (WHI) hormone therapy (HT) clinical trial (both estrogen and estrogen + progestin) of venous thromboembolism (VTE) risk and markers of reproductive life related to lifetime endogenous estrogen exposure . These markers included ages at menarche and menopause, number of term pregnancies (parity), bilateral oophorectomy, or time since menopause. Interactions of HT with these characteristics on VTE risk were also evaluated. Postmenopausal women without a history of VTE at baseline ([i]n[/i] = 27,035) were included in the analysis; the mean follow-up was 6.2 years.
There was no interaction between the individual markers and treatment assignment on the risk of a first VTE event found in the analysis. A pooled analysis of first VTE event by individual markers also did not find significant associations. However, pooled analyses restricted to first non-procedure-related VTE event found a significant interaction ([i]p[/i] < 0.01) for age at menopause (a U-shaped relationship). Relative to women having their menopause in their forties, those with early menopause (age < 40 years) or late menopause (age > 55 years) were at significantly greater risk for VTE. Analyses for deep vein thrombosis but not for pulmonary embolism and age at menopause yielded similar results.
James H. Pickar
Obstetrics and Gynecology, Columbia University Medical Center, New York, NY, USA
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