Polycystic ovary syndrome is a common hormone-related condition that causes women to develop fluid-filled cysts in their ovaries. It can also lead to other symptoms such as irregular menstrual periods, infertility, acne and excessive hair growth. According to the National Women's Health Information Center, the exact cause of polycystic ovary syndrome is not known; however, researchers believe that a combination of factors such as genetics, insulin resistance, low-grade inflammation and congenital exposure to androgens may be involved.
Congenital Exposure to Androgens
Women with polycystic ovary syndrome are known to produce an abnormal amount of androgens--hormones such as testosterone that are responsible for male reproductive development. According to the American Congress of Obstetricians and Gynecologists, high amounts of androgen can prevent ovulation and cause infertility and abnormal hair growth that are characteristic of the syndrome. Research suggests that fetal exposure to high amounts of androgens may indirectly cause polycystic ovary syndrome by altering fetal development. According to the Mayo Clinic, excess androgen in utero can cause a female fetus to develop a pattern of fat distribution around the abdomen that is more typical with males. This may lead to low-grade inflammation and insulin resistance--both of which are risk factors for developing polycystic ovary syndrome. More research is needed to clarify how and why this occurs.
Insulin Resistance
There is some evidence linking insulin resistance to the development of polycystic ovary syndrome. Insulin is a hormone that metabolizes or breaks down sugar, fats and proteins for the body and brain to use as energy. Insulin resistance is a condition in which the body's cells are immune to normal amounts of insulin, causing the pancreas to secrete more insulin in an attempt to get the body's cells the energy they need. According to the Mayo Clinic, excessive amounts of insulin may increase production of androgen hormones by the ovaries, thereby increasing a woman's risk for developing polycystic ovary syndrome.
Inflammation
Some immune systems are highly sensitive to certain foods or airborne irritants and an immune system may recognize these substances as harmful. In response, the body will trigger an inflammatory response, increasing the production of white blood cells in an attempt to fight off infection. According to the Mayo Clinic, low-grade inflammation is commonly associated with polycystic ovary syndrome. This may occur because substances produced by white blood cells can cause insulin resistance, which is known to increase androgen production.
Genetics
There is some evidence that genes play a role in causing polycystic ovary syndrome, as women who develop the condition tend to have first-degree female relatives, such as a mother or a sister, who also have the disease. A review published in the September 2009 issue of "Gynecological Endocrinology" notes that while this familial link is suggestive of inherited factors, there is also evidence that environmental factors play a role in triggering the disease. For example, diet and exercise, stress around the time of puberty, metabolism and obesity may all interact with genes. The review finds that multiple genes have been implicated in polycystic ovary syndrome, each of which may cause the syndrome in different ways. For example, some are involved in insulin resistance, others interfere with the production and action of androgens, and still others are responsible for encoding inflammatory proteins released by cells. Further study is needed to determine the precise role of genetic mutations and how they interact with environmental cues.
References
- Mayo Clinic: Causes of Polycystic Ovary Syndrome
- The American Congress of Obstetricians and Gynecologists: PCOS
- "Gynecological Endocrinology"; The Role of Genes in the Polycystic Ovary Syndrome-Predisposition and Mechanisms. E. Deligeoroglou, et al.; September 2009
