The latest results from the Women’s Health Initiative Hormone Trials provide new details on risks and benefits of therapy across age groups and time.
The conclusion that hormone therapy is not recommended for the prevention of chronic disease, but may remain a reasonable option for the short-term management of menopausal symptoms for younger women has been reaffirmed by Women’s Health Initiative (WHI) Hormone Trials investigators. This conclusion was reached after investigators reviewed data from the trial and the extended post-trial follow-up period.
The update and overview presents for the first time the extended follow-up data and highlights findings related to conditions that affect quality of life. The paper also provides the most comprehensive look at the trials’ findings to date, with more detail on individual disease-specific outcomes, side-by-side comparisons of estrogen-alone and estrogen plus progestin, and a full breakdown of results by age and over time.
The WHI, which is sponsored by the National Institutes of Health’s National Heart, Lung, and Blood Institute (NHLBI), followed women during a 13-year period.
“The combination of the 6 to 7 years of intervention combined with the extended post-intervention follow-up make these hormone therapy medications among the best studied medications in medical history,” said Dr. JoAnn Manson, a principal investigator for the WHI; chief of the division of preventive medicine at Brigham and Women’s Hospital; and professor of medicine at Harvard Medical School, Boston. “There are very few other treatments with this much information about the balance of benefits and risks over such a long period of time that include such a long post-intervention phase. The ultimate goal of this paper and the analysis is to help women and their health care providers make informed decisions.”
Of the 27,247 women who participated in the original WHI Hormone Trials-16,608 with an intact uterus in the trial of estrogen plus progestin and 10,739 without a uterus in the trial of estrogen alone-81% agreed to continue follow-up after the planned end of the trials. The WHI compared the rates of developing coronary heart disease (including a heart attack), stroke, breast cancer, blood clots in the lungs, colorectal cancer, endometrial cancer, hip fracture, and death among women who were assigned to hormones versus women who were assigned to placebo study pills.
Those chronic diseases and deaths were combined in a global index to provide an overall measure of the balance of harm and benefit. The WHI researchers also studied several other important outcomes, including dementia, other cancers, other fractures, diabetes, gallbladder disease, urinary incontinence, and quality-of-life outcomes such as hot flashes, night sweats, sleep disturbances, mood and depression, breast tenderness, and joint pain.
Rates of overall illnesses (any one of the major illnesses studied) and death were 12% higher in women taking estrogen plus progestin than in women taking placebo pills during the trial. In absolute numbers, there were 20 more major illnesses or deaths per year for every 10,000 women taking estrogen plus progestin compared with the same number of women taking placebo. After women stopped taking the estrogen plus progestin therapy, there were no effects on overall illness and death. These results were the same in each age group but absolute numbers of additional illnesses and deaths were low in women aged 50 to 59 years (12 more for every 10,000 women per year). The results are based on a trial period of 5.6 years with an average of 3 years of actual hormone use and then no hormone use for 8 or more years.
In women taking estrogen-alone, rates of overall illness and death were similar to those for placebo during and after the trial. However, these results differed importantly by age. For women in their 50s taking estrogen alone, there was a 16% reduced risk of overall illness and death. In absolute numbers, there were 19 fewer major illnesses or deaths per year for every 10,000 women in this age group compared with the same number taking placebo. Women in their 70s taking estrogen-alone had a 17% increased risk of overall illness and death, with 51 more major illnesses or deaths per 10,000 women per year compared with placebo. This pattern of results was seen during the main trial of 7 years with an average of 4 years of actual hormone use; with additional follow-up of 7 or more years, the findings became more statistically significant.
The paper adds information about common conditions and diseases in postmenopausal women which affect their health and quality of life. In both regimens, diabetes risk is decreased by 14% to 19%, while risks of gallbladder disease and urinary incontinence are increased by 50% to 60%. Benefit for diabetes and risks of urinary incontinence and gallbladder disease lessened after the drugs were stopped.
“Decisions about hormone therapy are not easy, but these findings provide an evidence base for finding a way forward,” said Jacques Rossouw, MD, chief of the WHI branch within the NHLBI’s Division of Cardiovascular Sciences. “Hormone therapy affects many organ systems in the body and changes the risks of many diseases-some in good ways, others in bad ways. Depending on hysterectomy status, age, and other individual factors, the consequences can vary dramatically. The WHI emphasizes the need for women to talk about their risk factors with their doctors before making any decisions regarding hormone therapy.”
“The Women’s Health Initiative has been a transformative study that has had a dramatic effect on medical practice,” said Michael Lauer, MD, director of NHLBI’s Division of Cardiovascular Sciences. “The in-depth analysis of intervention trial data and 13 years of cumulative data provided in this paper will help clinicians and women make informed decisions as to hormone therapy use.”
National Institutes of Health. Women’s Health Initiative reaffirms use of short-term hormone replacement therapy for younger women [press release]. Available here. Accessed October 24, 2013.