Endocrine Abstracts

The Women's Health Initiative (WHI) trial and Million Women's Study (MWS) fundamentally changed our understanding of risks and benefits associated with HRT. WHI for the first time provided evidence of harmful effects of HRT on the cardiovascular system and also confirmed significantly increased risk of breast cancer previously documented in a meta analysis. HRT does not decrease, and may in fact increase, the incidence of ishaemic heart disease. The risk of stroke is increased both with estrogen/progestogen and estrogen alone by approximately 40% and the risk of venous thromboembolism (VTE) is increased two- to four fold. The risk of breast cancer is related to the duration of treatment. The combined estrogen/progestogen preparations appear to be associated with a greater risk than estrogen alone. HRT is effective for prevention and treatment of osteoporosis, but should be used for this purpose only in the short-term in women who also have menopausal symptoms. The effects of HRT on health-related quality of life mainly depends on the presence of menopausal symptoms. HRT does not protect against cognitive impairment in women over the age of 65 years but might positively affect cognition in younger postmenopausal women. Short-term HRT is appropriate for postmenopausal women who have moderate to severe symptoms associated with estrogen deficiency. It seems justifiable to use the lowest estrogen dose whenever possible. WHI trial provided data only for oral conjugate equine estrogens combined with medroxyprogesterone acetate. There is a possibility that other routes of administration might be safer,at least there is such evidence for transdermal estradiol in terms of the risk of VTE. Results from WHI and similar trials cannot be extrapolated to women with premature menopause.