Early initiation of menopausal hormone therapy (MHT) improves some markers of cardiovascular disease (CVD) but does not affect the progression of atherosclerosis, according to a study being published in Annals of Internal Medicine.

CVD is the leading cause of death in women and incidence increases after menopause. Research suggests that cardiovascular benefits of MHT may be limited to women who begin treatment at a younger age, closer to menopause, or both. Researchers conducted a randomized controlled trial of MHT in women who were within 36 months of their last menses to assess effects of early initiation of oral or transdermal MHT versus placebo on rates of progression of atherosclerosis. Participants were 727 healthy women between the ages of 42 and 58 who were at low risk for CVD.

Over four years, the women were randomly assigned to receive oral conjugated equine estrogens, 0.45 mg/d (n=230), transdermal 17β-estradiol, 50 mcg/d (n=222), each with 200 mg of oral progesterone for 12 days per month, or placebo (n=275). Compared to placebo, the two low-dose MHT regimens favorably altered certain CVD risk factors. However, vascular imaging at baseline and at four years showed that MHT had a neutral effect on atherosclerosis progression.