Hormone therapy for younger postmenopausal women: how can we make sense out of the evidence?

The Women's Health Initiative (WHI) trials have provided us with valuable information on the effect of hormone therapy (HT) in older postmenopausal women. These results have been generalized to women of all ages, despite the fact that the trials were not powered to evaluate the effect of HT in younger women who initiate treatment shortly after menopause. Pooled data from the WHI and other randomized trials now reveal that HT in younger women is associated with a reduction in coronary heart disease events and total mortality, a benefit that is not seen in older women.