Hormone replacement therapy (HRT) in recently menopausal or perimenopausal women may offer protection against cardiovascular disease without increasing cancer risk, according to a study published Oct. 9 in BMJ.
Louise Lind Schierbeck, MD, of Hvidovre Hospital in Denmark, and colleagues used data from the Danish Osteoporosis Prevention Study to identify healthy, recently postmenopausal white women aged 45 to 58. They excluded women with a history of bone disease, chronic disease, current or past cancer or thromboembolic disease, current or past treatment with glucocorticoids, current or previous HRT and drug or alcohol dependence.
Between 1990 and 1993, they enrolled 1,006 women to participate in a randomized study; of these, 502 received HRT; the remainder were assigned to a control group that received no treatment. The participants had a mean age of 49.7 years, mean body mass index of 25.2, and mean time since menopause of seven months.
The study's planned duration was 20 years, but when the results of other studies published near the current study's 10-year mark indicated HRT might produce more harm than benefit, the researchers advised participants to discontinue therapy. They continued to follow the participants, obtaining data on changes in vital status through the Danish civil registration system, and hospital contacts through the Danish national hospital discharge register. The follow-up period ended in June 2008.
The authors followed participants for a mean of 15.8 years. During this period 67 women died, 40 in the control group and 27 in the group that received HRT. Heart failure was diagnosed in 11 patients (eight in the control group and three in the treated group), and 16 received a diagnosis of MI (11 in control group and five in treated group).
The authors reported no difference in rates of stroke, venous thromboembolism or pulmonary embolism between the two groups.
Cancer rates did not differ significantly between the groups; 43 members of the control group and 52 members of the treated group developed some type of cancer; because of its association with HRT, the authors analyzed rates for breast cancer and found no statistically significant differences among the two groups (26 in control group vs. 24 in treated group).
However, "A significant interaction was found between hormone replacement therapy and age at baseline for the composite endpoint [of] mortality or breast cancer, with the younger women (less than 50 years) receiving hormone therapy having significantly reduced risk," the authors wrote.