What exactly did the notorious WHI (Women's Health Initiative) study show?
It is well established menopausal HRT with estrogen alone or estrogen combined with progesterone or progestin significantly relieves symptoms of menopause and prevents osteoporosis.[1-4] However, in 2002, the principal results of the Women’s Health Initiative (WHI) trial were published in the prestigious Journal of the American Medical Association.
Note: As described elsewhere What are Bioidentical Hormones CEE and MPA are non-bioidentical hormones.
These are the type of hormones that were used in the well-known WHI studies.
In an upcoming article we will outline the effects of bioidentical HRT, and contrast bioidentical estrogen/progesterone with non-bioidentical estrogen/progestin.
The planned duration of the study was 8.5 years, however it was stopped early after 5.2 years because the incidence of invasive breast cancer exceeded the acceptable rate and the global index statistic showed that risks were exceeding benefits. More specifically, the results showed the following in the CCE + MPA group:
- 26% increased risk of breast cancer
- 29% increased risk of myocardial infarction or death from cardiovascular disease
- 41% increased risk of cerebral vascular accident
- 200% increased risk of venous thrombotic disease/embolism, deep vein thrombosis, and pulmonary embolism (blockage of an artery in the lungs by fat, air, a blood clot, or tumor cells).
The conclusions drawn from this study was that administration of 0.625 mg/day of CEE and 2.5 mg/day of MPA is not appropriate for the primary prevention of cardiovascular disease in menopausal women, and furthermore increases risk of invasive breast cancer, cerebrovascular accident, venous thromboembolism, deep vein thrombosis, and pulmonary embolism.
What about estrogen only HRT
(aka estrogen monotherapy or unopposed estrogen therapy)?
Because progestin markedly increases the risk of breast cancer relative to estrogen use alone , a WHI follow up study investigated menopause therapy with estrogen only. Enrolled were 10,739 postmenopausal women, aged 50-79 years, with prior hysterectomy (surgery that removes the uterus). The intervention was non-bioidentical estrogen (conjugated equine estrogen [CEE]) 0.625 mg/day or placebo. After 6.8 years, this study was also terminated early because of unacceptable risk-to-benefit ratio. The alarming results were:
Aftermath of the WHI studies
Widespread media coverage of results of the WHI studies led to a marked decline in sales and use of postmenopausal hormones. One year following the publication of WHI results, prescriptions for Prempro® (horse urine-derived estrogens and a synthetic progestin, both non-bioidentical hormones) fell by 66% and those for Premarin® (horse urine-derived estrogens, non-bioidentical) fell by 33%.
Alternative solutions to treatment of menopausal symptoms
Studies show that bioidentical estrogen and biodentical progesterone is one solution to achieve this. We will cover this in upcoming articles.
The other less well acknowledged, albeit effective, solution is testosterone therapy for menopausal women, which we have covered in a previous articles:
Testosterone Therapy vs. Estrogen Therapy in Surgically Menopausal Women - effectiveness comparison
Beneficial effects of testosterone therapy on menopause symptoms and quality of life
Testosterone in women - is it physiological and clinically important?
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2. Morris EP, Burbos N. Menopausal symptoms. Clinical evidence. 2010;2010.
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4. National Institutes of Health State-of-the-Science Conference statement: management of menopause-related symptoms. Ann. Intern. Med. Jun 21 2005;142(12 Pt 1):1003-1013.
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