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Estrogen and associated diseases

Last updated: January 15, 2021

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Estrogen is a female sex hormone that is produced in the ovaries and, to a lesser degree, in the adrenal glands and adipose tissues. It is essential for the development of primary and secondary sex characteristics, as well as function of the reproductive organs. Estrogen also plays a role in several other processes, including bone metabolism and liver function. While ovarian insufficiency, aromatase deficiency, and hyperprolactinemia result in pathologically low estrogen levels, a decrease in estrogen is a normal feature of menopause. Possible symptoms of estrogen deficiency include menopausal symptoms, vaginal and endometrial atrophy, and osteoporosis. Increased estrogen levels may also have adverse effects, including gynecomastia, thrombosis, and an increased risk of breast and endometrial cancer.

Ovarian estrogen synthesis

Estrogen synthesis primarily takes place in the ovarian granulosa cells.

Extra-ovarian estrogen synthesis [1]

Estrogen is also produced in other aromatase-containing tissues:

Estrogen types

There are three types of estrogen: estradiol, estrone, and estriol.

Obesity increases the risk of postmenopausal breast cancer. It is hypothesized that this is due to estrogen production in adipose tissue. [2]

Measurement of unconjugated estriol (uE3 or free estriol) is part of the prenatal screening for fetal anomalies (i.e., triple screen test and quad screen test). Decreased levels are associated with Down syndrome, Edward syndrome, molar pregnancy, and fetal demise.

Estrogen is a steroid hormone that promotes female sexual development and stimulates the growth and maturation of primary and secondary sex characteristics.

Genitalia/sex characteristics

Extragenital tissue [4][5]

Adverse effects of estrogen can arise from high levels secondary to increased endogenous production or medication (e.g., hormone replacement therapy during menopause):

Although estrogen is a risk factor for the development of some types of cancer, it reduces the risk of colon cancer.

High estrogen levels increase the risk of thrombosis.

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  2. Cleary MP, Grossmann ME. Obesity and breast cancer: the estrogen connection. Endocrinology. 2009; 150 (6): p.2537–2542. doi: 10.1210/en.2009-0070 . | Open in Read by QxMD
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  4. Björnsson ES. Hepatotoxicity by drugs: the most common implicated agents. Int J Mol Sci.. 2016; 17 (2): p.224. doi: 10.3390/ijms17020224 . | Open in Read by QxMD
  5. Gorodeski GI. Effects of menopause and estrogen on cervical epithelial permeability. J Clin Endocrinol Metab. 2000; 85 (7): p.2584-2595. doi: 10.1210/jcem.85.7.6671 . | Open in Read by QxMD
  6. Stachenfeld NS. Sex Hormone Effects on Body Fluid Regulation. Exerc Sport Sci Rev. . 2008; 36 (3): p.152–159. doi: 10.1097/JES.0b013e31817be928. . | Open in Read by QxMD
  7. Miller VM, Duckles SP. Vascular actions of estrogens: functional implications. Pharmacol Rev.. 2008; 60 (2): p.210–241. doi: 10.1124/pr.107.08002 . | Open in Read by QxMD
  8. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. McGraw-Hill Education ; 2015