Women who take oestrogen may decrease their risk of developing atherosclerosis - the progressive narrowing and hardening of the arteries - according to new research published in the March issue of The Journal of Clinical Endocrinology & Metabolism (JCEM).
Researchers at the Mayo Clinic in Rochester, Minnesota, examined the relationship between oestrogen and atherosclerosis in the coronary arteries of 56 deceased women between the ages of 18 and 98 years. Forty-six of the women were post-menopausal, while 10 were pre-menopausal.
Through the examination of medical records and coronary arteries during autopsy, researchers discovered that calcium content, or hardening of the arteries, was 90 per cent lower in women on oestrogen replacement therapy (ERT) than in untreated (non ERT) post-menopausal women. Additionally, plaque area was not significantly different between pre-menopausal women and post-menopausal women on HRT.
"Our data indicates a strong negative association between oestrogen status in women and both coronary calcium and plaque," said Dr Lorraine Fitzpatrick, Professor of Medicine at the Mayo Medical School and the principle investigator on the study. "This finding suggests that oestrogen may slow the progress of coronary calcification and plaque formation."
In all of the women, oestrogen status, age, diabetes and hypertension were single predictors of both calcium and plaque areas. Additionally, researchers discovered a significant age variation among the postmenopausal women who did not use ERT, but not among the women who used ERT or pre-menopausal women.
Although previous studies have suggested that oestrogen replacement therapy reduces a woman's risk of coronary heart disease, the Mayo study is the first to examine the association of oestrogen status with the true calcium content of atheromatous plaques. The study's findings are consistent with previous observational studies, which have suggested that oestrogen protects a woman's heart.
"As women reach the age of menopause and work with their doctors to determine whether they will take hormone replacement therapy, it is important for them to consider their risks for developing heart disease," said Dr Fitzpatrick. "This research helps us better understand the role that hormone replacement therapy plays in women's bodies and, especially on their heart. Larger, prospective clinical trials of longer duration are needed to further understand the role of oestrogen in the prevention of coronary artery disease."