New data emerges on use of hormone therapy
Since results of the 2002 Women's Health Initiative (WHI) report suggested that use of menopausal hormone therapy increases risk of coronary heart disease,1 science has examined the timing of therapy initiation on safe use of such treatment. A new report offers reassuring data for hormone therapy use in recently menopausal women.2
Using data from the California Teachers Cohort Study, a prospective study of more than 133,000 current and retired female teachers and administrators, the new analysis assesses how age at which hormone therapy is used impacts cardiovascular and overall mortality.
The study results add to the growing evidence that hormone use might have a beneficial effect in younger women but has little cardiovascular benefit in older women, says Daniel Stram, PhD, professor in the Department of Preventive Medicine, Keck School of Medicine, at the University of Southern California in Los Angeles. The findings also have direct implications regarding the lack of potential benefits of continued use of hormone therapy for older women who began use close to menopause, he notes.2
When it comes to the benefits of hormone therapy on coronary heart disease incidence or mortality, scientists have theorized that it is the time when a woman begins hormone therapy (her age or the time since her menopause) that has led to discrepancies between observational study results and those of randomized trials.3-4 Reviews of previous data have indicated that any benefit of hormone therapy on cardiovascular disease is restricted to women who started therapy within 10 years of menopause.5,6 Age at randomization might modify the effect of hormone therapy on risks of overall mortality and coronary heart disease incidence, as seen in the WHI data3, and women ages 50-59 when randomized to HT had a reduced risk of mortality overall, scientists observe.
Look at the results
To conduct the analysis of data from California Teachers Cohort Study, scientists looked at current and retired female teachers and administrators who returned an initial questionnaire during 1995-1996. Participants then were followed until late 2004 or until death. More than 71,000 participants were eligible for analysis for the current study. Analysis was adjusted for a variety of potential cardiovascular and other confounders.
During follow-up, deaths occurred in 18.3% of never-users of hormone therapy and 17.9% of former users. In contrast, deaths occurred in 6.9% of women taking hormone therapy at the time of the baseline questionnaire.
In the overall analysis, current hormone therapy use was associated with a reduced risk of coronary heart disease mortality (hazard ratio [HR]0.84, 95% confidence interval [CI] 0.74-0.95). The reduction was most notable in the youngest users (ages 36-59, HR 0.38), with a gradual rise as the age of current therapy users increased, reaching a hazard ratio of about 0.9 in current users age 70 and older. The coronary heart disease mortality hazard ratio did not reach or exceed the hazard ratio (1.0) assigned to never-users of any age. In looking at overall mortality, the hazard ratio was 0.54 for the youngest current users, approaching 1.0 in the oldest current users. The associations between overall and coronary heart disease mortality were similar among users of estrogen-only and estrogen-progestin therapy users.2
The pendulum continues to swing toward reassurance regarding timing of menopausal hormone therapy and cardiovascular mortality, says Andrew Kaunitz, MD, professor of obstetrics and gynecology at the University of Florida College of Medicine in Jacksonville, FL. Age, or time since menopause, clearly does matter, particularly in regard to coronary heart disease mortality and hormone therapy use, he remarks.
The findings from the current study fall in line with previous reports in women and nonhuman primates that support the safety of hormone therapy when used by recently menopausal woman with bothersome symptoms, Kaunitz says.
References
- Manson JE, Hsia J, Johnson KC, et al. Estrogen plus progestin and the risk of coronary heart disease. N Engl J Med 2003; 349:523-534.
- Stram DO, Liu Y, Henderson KD, et al. Age-specific effects of hormone therapy use on overall mortality and ischemic heart disease mortality among women in the California Teachers Study. Menopause 2011; 18:253-261.
- Rossouw JE, Prentice RL, Manson JE, et al. Postmenopausal hormone therapy and risk of cardiovascular disease by age and years since menopause. JAMA 2007; 297:1,465-1,477.
- Willett WC, Manson JE, Grodstein F, et al. Re: "combined postmenopausal hormone therapy and cardiovascular disease: toward resolving the discrepancy between observational studies and the Women's Health Initiative clinical trial." Am J Epidemiol 2006; 163:1,067-1,068; author reply 1,068-1,069.
- Grodstein F, Manson JE, Stampfer MJ. Hormone therapy and coronary heart disease: the role of time since menopause and age at hormone initiation. J Womens Health (Larchmt) 2006; 15:35-44.
- Hernan MA, Alonso A, Logan R, et al. Observational studies analyzed like randomized experiments: an application to postmenopausal hormone therapy and coronary heart disease. Epidemiology 2008; 19:766-779.
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