Estrogen Therapy For Menopause

Summary: Review of health benefits and risks of estrogen on post-menopausal women

Interestingness: 2

Paper by Kathryn A Martin MD in the Journal of Anti-Aging Medicine, Volume 1, Issue 4, Winter 1998.

(((This paper is a dense but nicely written review of the effects of estrogen on post-menopausal women. It is hard to summarise since it already is a summary. I'm going to pick out interesting snippets)))

The postmenopausal ovary produces almost no estrogen. Estrogen in postmenopausal women is mainly produced by conversion of androstendedione (((don't know where that happens))). Average age of menopause is 51 (((or was back then, and probably in the USA. Last third of their life spent with assumedly little estrogen, although there is no plot or numbers of levels of estrogen in the paper))).

Some problems associated with this drop in estrogen are vaginal dryness, pain during sex and symptoms similar to urinary tract infection. Hot flushes are also experienced by 75% of women which commonly leads to insomnia and its derivative problems. Osteoporosis is also common, and the risk of coronary heart disease (CHD) goes up by a lot (((doesn't say))). Estrogen in hormone replacement therapy (HRT) helps with the flushes, and the vaginal and urinary tract problems. It also stops the osteoporosis and decreases the risk of CHD (((by 50% it seems from later in the paper))) when given in doses equivalent to 625 micrograms in conjugated form, or equivalent. Although a 15-year study on postmenopausal women did not notice any difference between estrogen and non-estrogen users with respect to cognitive function, a meta-analysis of epidemiological and control studies claims the risk of dementia for estrogen users to be 0.71 (0.53-0.96) compared to non-users (((but the paper abstract discourages that conclusion))).

Five types of HRT are used:

• estrogen only (625 micrograms conjugated)
• cyclic combined: estrogen (625 micrograms conjugated) for days 1-25 of the month, medroxy-progesterone acetate (MPA, a progestin), 5mg, days 13-25. This is the most popular option.
• continuous combined: estrogen (625 micrograms conjugated), and MPA (2.5 mg) without breaks.
• other estrogen preparations: Different variants all equivalent to the 625 micrograms of conjugated estrogen. Some as vaginal creams.
• low dose contraceptives: these are mostly used by women around menopause time

Risks of HRT when supplying only estrogen include increased risks of gallstones, endometrial hyperplasia and cancer (((uterus))), and breast cancer. The increase in uterine cancer can be cancelled by adding in progestin, but it doesn't seem to help with the breast cancer. Breast cancer risk is a factor of 1.35 (1.21-1.49) compared to baseline after 5 years of HRT.

Estrogen raises high density lipoprotein (HDL) and decreases low-density lipoprotein (LDL), but progestin has the opposite effect (((although it later says that women under the combined therapy had HDL levels similar to women only taking estrogen, and that the protective effects against CHD were similar in both groups))). Estrogen suppresses platelet function and is a potent vasodilator. It also improved 10-year survival of women with narrowing of their coronary arteries. On a different study though, HRT did not improve survival of women with CHD and risk of events (((heart attacks?))) was higher during the first year compared to placebo.

Some new substances can act as estrogen agonists in some tissue and estrogen antagonists in others. Raloxifene, for example, appeared, in one study, to have an estrogen agonist effect with respect to osteoporosis and lipid profile, but antagonist with respect to breast and endometrial tissue. Even though it affected lipids in a positive way, it did not show improvement with respect to artherosclerosis.

(((Summary: I don't think it'd have a major effect on longevity)))

Abstract follows:

The medical management of menopause continues to be a topic of controversy. Although many of the benefits of estrogen therapy have been well established (treatment of estrogendeficiency symptoms, prevention of osteoporosis, and prevention of coronary heart disease), the potential risks of breast cancer are of great concern. Although many postmenopausal women are candidates for hormone replacement therapy (HRT), many choose not to take it because of fear of breast cancer or concerns about potential side effects and continued menstrual bleeding. Therefore, making choices about potential therapies after menopause can be a difficult one for both women and their health care providers. An important principle of HRT is the notion of short-term versus long-term use, as the goals of both therapy and riskbenefit profiles are different. Although most perimenopausal and postmenopausal women are candidates for short-term HRT (with the exception of those with a history of breast cancer), no general consensus is found regarding who should or should not receive long-term HRT. Other new areas of clinical investigation in the field of menopause and HRT include the possible impact of estrogen on cognitive function, the role of exogenous androgen replacement for libido, and the role of a new class of drugs known as "selective estrogen receptor modulators" (SERMs). Given this rapidly changing field, it is likely that the medical management of menopause will continue to evolve in the coming years.