Secreted mainly by the ovaries and corpus luteum in women, progesterone and estrogen play important roles in development and reproduction. Good health requires that these hormones remain in balance. According to the book "What's Your Menopause Type?" by Joseph Collins, nonpregnant women should have a progesterone to estrogen ratio of at least 20 to 1. When this ratio decreases, patients may develop a syndrome called estrogen dominance. This pathological condition can produce several medical disorders which have serious consequences.
Autoimmune Disease
According a 2010 report in the journal "Lupus," estrogen may contribute to the appearance of autoimmune disease in women, especially systemic lupus erythematosus. Patients with this condition often experience inflammation of organs and tissues. The cause of SLE remains unknown and no cure exists, yet the symptoms can be safely treated.
The experiment described in "Lupus" established a link between the genes responsible for estrogen metabolism and the development of lupus erythematosus. Women with a specific estrogen genotype, called PPXX, have the greatest risk of acquiring SLE because they appear more susceptible to changes in estrogen metabolism. Such patients should closely monitor their estrogen levels, and they should not take estrogenic drugs.
Polycystic Ovary Syndrome
A 2010 investigation published in the "Journal of Clinical Endocrinology & Metabolism" looked at hormone levels in females with polycystic ovary syndrome. This disorder affects about 10 percent of all women. Lack of ovulation and menstruation typically indicate ovarian disease, and these symptoms often lead to infertility.
The "JCEM" study found that women with ovarian disease had elevated levels of most sex steroids including estrogen and testosterone. This increase led to estrogen dominance. A subtype of estrogen, estrone, was the best predictor of polycystic ovary syndrome. Thus, simple diagnostic tests can reveal estrogen dominance and a woman's risk of acquiring ovarian disease.
Endometrial Hyperplasia
The website Womenshealth.gov suggests that polycystic ovary syndrome may develop into endometrial hyperplasia and endometrial cancer in women. Elevated levels of estrogen contribute to these medical conditions, as well. Thus, taking exogenous estrogen as a part of hormone replacement therapy may cause side effects.
The authors of a 2005 paper in the periodical "Lancet" examined the relationship between estrogen and cancer as part of the Million Women Study. Postmenopausal women taking exogenous estrogen had a greater risk of developing endometrial cancer than women not taking hormones. Patients, therefore, should carefully consider the risks and benefits of estrogen-only preparations before using them.
Breast Cancer
Exposure to high levels of estrogen also correlates with an increase in breast cancer risk. A 2002 analysis published in the "Journal of the National Cancer Institute" re-evaluated nine studies testing that hypothesis in postmenopausal women. Results indicated that high levels of all the sex steroids measured increased breast cancer risk. Specifically, the risk for women with the highest levels of estrogen was double that of women with the lowest levels. Hormone replacement therapy, which can re-establish the proper balance between progesterone and estrogen, decreased this risk, but these results did not reach statistical significance. That correlation, therefore, requires additional confirmation.
References
- "Lupus"; Association of Estrogen and Aromatase Gene Polymorphisms with Systemic Lupus Erythematosus; J. Wang et al.; 2010
- "Journal of Clinical Endocrinology & Metabolism"; Are There Any Sensitive and Specific Sex Steroid Markers for Polycystic Ovary Syndrome?; E. Stener-Victorin et al.; February 2010
- Womenshealth.gov: Polycystic Ovary Syndrome (PCOS)
- "Lancet"; Endometrial Cancer and Hormone-Replacement Therapy in the Million Women Study; V. Beral et al.; April 30, 2005
- "Journal of the National Cancer Institute": Endogenous Sex Hormones and Breast Cancer in Postmenopausal Women: Reanalysis of Nine Prospective Studies
