WASHINGTON -- Taking hormone therapy to treat menopausal symptoms like hot flashes does not increase a woman's risk of early death, according to a long-term follow-up of trials that were stopped early due to health concerns.
The Women's Health Initiative (WHI) research completely changed the understanding of the risks and benefits of hormone therapy in 2002 when it linked the treatments involving estrogen plus progestin, and estrogen alone, the most common formulations of hormone therapy, to an increased risk of stroke and breast cancer.
The new study, led by investigators at the US Brigham and Women's Hospital (BWH), examined the long-term rates of death from all-causes, and the rates of death from specific causes, including cardiovascular disease, cancer and other major illnesses over a follow-up of 18 years among 27,347 women from the two WHI hormone therapy trials.
"In this new analysis, we found that there was no association between hormone therapy and all-cause mortality during either the treatment period or the long-term follow-up of these trials," lead author JoAnn Manson, chief of the division of preventive medicine at the BWH.
Researchers used data from the two trials which included postmenopausal women with an average age of 63 at enrollment and explored the effect of treatment which was stopped early after five to seven years because of an increased risk of stroke or breast cancer.
During the cumulative 18-year follow-up, 7,489 deaths occurred.
The researchers found during the five to seven years of treatment, death rates were about 30 percent lower among women aged 50 to 59 when they received hormone therapy than when they received placebo.
However, among women who initiated hormone therapy in their 60s and 70s, no effect on death rate was observed.
After 18 years, which included 10 to 12 years of follow-up after stopping hormone therapy, the differences by age group diminished and were no longer statistically significant.
Over the extended follow-up period, overall mortality rates and deaths from cardiovascular disease and cancer were neither increased nor decreased among women who received hormone therapy.
The researchers also found that deaths from Alzheimer's disease and other forms of dementia were significantly lower with estrogen alone than with placebo during 18 years of follow-up, but the use of estrogen plus progestin was not associated with dementia mortality.
"These findings provide support for clinical guidelines endorsing the use of hormone therapy for recently menopausal women to manage bothersome hot flashes and other menopausal symptoms," Manson said. "However, the findings do not provide support for the use of hormone therapy for the prevention of cardiovascular disease or other chronic diseases."
"In clinical decision making, these considerations must be weighed against the impact of untreated menopausal symptoms that women experience, including impaired quality of life, disrupted sleep, reduced work productivity, and increased health care expenditures," she added.
The findings were published Tuesday in the US journal JAMA. (Xinhua)