In the human body, the breakdown of androgens---or masculine hormones---produces estrogens, which are feminine hormones. Good health in men and women requires a proper balance between androgens, estrogens and their parent compound, progesterone. Women in particular should carefully monitor their estrogen levels as changes can reveal disease. When measuring estrogen, three distinct components become apparent. Each of these substances plays a unique role in physiology and behavior.
Estrone
Levels of estrone, also called E1, remain low in most premenopausal women. Yet estrone is the only form of estrogen measurable in postmenopausal women. Hormone therapy can affect E1 levels irrespective of menopause status. A 2010 investigation published in the "Journal of Thrombosis and Haemostasis" looked at the role of estrone in blood clotting. This study tested women on hormone replacement therapy with patients receiving estrogen by mouth or by skin. Oral administration produced large amounts of E1, which correlated with the production of thrombin, an enzyme causing blood clots---thus the oral intake of estrogen increased the risk of clotting. Transdermal administration produced lower levels of E1 as estrogen enters the bloodstream through a different metabolic pathway when using a patch. Women taking hormone therapy must properly regulate their estrone levels because altering this estrogen component can increase clotting risk.
Estradiol
Estradiol, or E2, is the most abundant form of estrogen in premenopausal women. It contributes to development and reproduction and also affects bone health. A 2002 experiment described in the "Journal of Bone and Mineral Metabolism" investigated the correlation between endogenous estradiol levels and bone mineral density. The latter indicator of bone health decreases with age, and this change parallels decreases in E2. The 2002 study tested three groups of women: premenopausal, perimenopasual and postmenopausal. Results indicated that estradiol levels can accurately predict bone health. The perimenopausal women, in particular, showed great sensitivity to changes in E2 levels. Maintaining adequate levels of estradiol during menopausal changes ensures bone health and reduces fracture risk.
Estriol
The estrogen component known as estriol, E3, impacts several bodily processes as well. Estriol levels are low in premenopausal women and are comparable to those found in men. Yet the amount of E3 increases dramatically during pregnancy. Unlike E1 and E2, this component of estrogen has little impact on breast development. However, according to a 2008 article published in "Life Extension Magazine," estriol supplements provide relief for menopausal symptoms without increasing cancer risk.
Estriol levels also serve as a warning sign for premature birth. A 2010 report in "Prenatal Diagnosis" studied the amount of E3 present in pregnant women's uteri. Patients with unusually high levels of E3 were more likely to prematurely enter labor. The mechanism underlying this correlation remains unknown, yet these data show the importance of closely monitoring estriol levels.
References
- "Journal of Thrombosis and Haemostasis"; Effect of Estrone on Thrombin Generation may Explain the Different Thrombotic Risk between Oral and Transdermal Hormone Replacement Therapy; C. N. Bagot et al.; 2010
- "Journal of Bone and Mineral Metabolism"; Relationship between Endogenous Estrogen, Sex Hormone-Binding Globulin, and Bone Loss in Female Residents of a Rural Japanese Community: The Taiji Study; N. Yoshimura et al.; 2002
- "Life Extension Magazine": Report: Estriol: Its Weakness is Its Strength
- "Prenatal Diagnosis"; Second Trimester Serum Predictors of Preterm Birth in a Population-Based Sample of Low-Risk Pregnancies; L. L. Jelliffe-Pawlowski et al.; 2010
