Polycystic Ovarian Syndrome (PCOS)
- Polycystic ovarian syndrome (PCOS) is a common endocrine disorder with heterogeneous manifestations that affects 6–10% of the U.S. population.
- Characterized by hyperandrogenism, insulin resistance, and anovulation, typically presenting as amenorrhea or oligomenorrhea
- Diagnostic clinical characteristics include menstrual dysfunction, infertility, hirsutism, acne, obesity, and metabolic syndrome.
- The ovaries are often polycystic on imaging.
- The etiology of PCOS is unknown, but presentation and course can be modified by lifestyle factors.
- System(s) affected: reproductive, endocrine/metabolic, skin/exocrine
- Synonym(s): Stein-Leventhal syndrome; polycystic ovary disease
- Condition may begin at puberty.
- Obesity may amplify PCOS, but it is not diagnostic.
- 20% of women with PCOS are not obese.
- Predisposes to and is associated with obesity, hypertension, diabetes, metabolic syndrome, hyperlipidemia, infertility, insulin-resistance syndrome, endometrial hyperplasia, and uterine cancer
Incidence and prevalence are still highly debated due to a wide spectrum of diagnostic features; the National Institutes of Health (NIH) criteria require chronic anovulation and hyperandrogenism.
- The prevalence based on NIH criteria is 7% of reproductive age women.
- Predominant age: reproductive age
- Predominant sex: females only
Etiology and Pathophysiology
- Recent evidence points to a primary role for insulin resistance with hyperinsulinemia.
- Increased GnRH pulsations in the hypothalamus lead to increased production of LH with limited production of FSH.
- Hyperandrogenism: Ovaries are the main source of excess androgens (75% of circulating testosterone originates in the ovary). Polycystic ovaries have thickened thecal layers and overexpressed LH receptors, which cause excess androgen secretion.
- Ovarian follicles: Abnormal androgen signaling may account for abnormal folliculogenesis causing polycystic ovaries.
- Obesity results in compensatory hyperinsulinemia: Women with PCOS have insulin resistance similar to that in type 2 diabetes. Elevated levels of insulin decrease sex hormone–binding globulin (SHBG), increasing bioavailability of testosterone. Insulin may also act directly on adrenal glands, ovaries, and hypothalamus to enhance androgen production.
- Insulin resistance causes elevated insulin levels and the frequently associated metabolic syndrome or frank diabetes mellitus.
- Likely a combination of polygenic and environmental factors
- Implicated genes include DENND1A and THADA.
See “Commonly Associated Conditions”; cause and effect are difficult to extricate in this disorder.
None known; focus on early diagnosis and treatment to prevent long-term complications.
Commonly Associated Conditions
- Obstructive sleep apnea
- Diabetes mellitus
- Endometrial hyperplasia/carcinoma
- Fatty liver disease
- Mood disturbances and depression
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Domino, Frank J., et al., editors. "Polycystic Ovarian Syndrome (PCOS)." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688927/1.1/Polycystic_Ovarian_Syndrome__PCOS_.
Polycystic Ovarian Syndrome (PCOS). In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688927/1.1/Polycystic_Ovarian_Syndrome__PCOS_. Accessed June 6, 2023.
Polycystic Ovarian Syndrome (PCOS). (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688927/1.1/Polycystic_Ovarian_Syndrome__PCOS_
Polycystic Ovarian Syndrome (PCOS) [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 June 06]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688927/1.1/Polycystic_Ovarian_Syndrome__PCOS_.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Polycystic Ovarian Syndrome (PCOS) ID - 1688927 ED - Domino,Frank J, ED - Baldor,Robert A, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688927/1.1/Polycystic_Ovarian_Syndrome__PCOS_ PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -