Long term hormone therapy for perimenopausal and postmenopausal women

Hormone therapy (HT) is widely used for controlling menopausal symptoms. It has also been used for the management and prevention of chronic diseases such as cardiovascular disease, osteoporosis and dementia in older women. The present review set out to assess the long term clinical effects of using HT. Nineteen randomised double-blind trials (involving 41,904 women aged 26 to 91 years) compared HT (all oestrogens, with or without progestogens, administered by oral, transdermal, subcutaneous or intranasal routes) with placebo when taken for at least one year. In healthy women (11 studies), combined continuous HT significantly increased the risk of obstruction of a vein by a blood clot (venous thrombo-embolism), fatal or nonfatal heart attack (after one year's use), stroke (after three years), breast cancer, gallbladder disease and (in women over 65 years) dementia. Long-term oestrogen alone significantly increased the risk of venous thromboembolism, stroke and gallbladder disease. Among women with cardiovascular disease (six studies) long-term use of combined HT significantly increased the risk of venous thromboembolism, particularly in the first two years of use, and gallbladder disease. HT offered the benefit of a significant reduction in the risk of fracture (no greater in women at high risk of fractures) or colorectal cancer but only after four or five years' treatment with HT, while the highest risk of cardiovascular events with combined HT occurred in the first year of use.