PCOS risk factors: genes, hormones and linked health risks

What PCOS is

Polycystic ovary syndrome (PCOS), also known as polyendocrine metabolic ovary syndrome (PMOS), is the name of a hormonal disorder. PCOS affects the ovaries, as well as many other parts of the body (MedlinePlus). Women with PCOS usually have at least two of these three features (NICHD):

• absence of ovulation, leading to irregular menstrual periods or no periods at all
• high levels of hormones called androgens, or signs of high androgens, such as increased body or facial hair
• growths in one or both ovaries, often clumps of ovarian follicles that have stopped developing

PCOS often develops as young as age 11 or 12, around the time of your first period, but you can develop it later (MedlinePlus).

What may cause PCOS

The exact cause of PCOS is unknown. Research has shown that different factors may play a role, including (MedlinePlus):

• Genetics. PCOS tends to run in families.
• Imbalances in androgen levels.
• Insulin resistance. This is a condition in which your body can't use insulin properly, which can lead to high blood glucose levels.

Research has shown that genetic and environmental factors contribute to the development of PCOS, but its exact cause remains unknown (NICHD).

Genes and family history

The symptoms of PCOS tend to run in families, so genetics have long been a focus of PCOS research. Recent research suggests that there are 19 possible changes, or variants, in genes that can increase a person's risk of developing PCOS. These variants could explain why the features and symptoms of PCOS are so different from one person to the next (NICHD).

Research conducted in animal models suggests that exposure to increased levels of androgen hormones in the womb may also increase the likelihood of PCOS in offspring (NICHD).

Hormones and insulin

Women with PCOS have higher levels of androgens and may have lower levels of estrogen. High levels of androgens can interfere with signals from the brain that control ovulation, making it occur sporadically or not at all (NICHD).

Many women with PCOS also have problems with insulin, which helps move sugar (glucose) from the bloodstream into cells. When cells don't respond normally to insulin, the level of sugar in the blood rises. The body then produces more and more insulin, and to balance out the high levels of insulin, the body makes more androgens, which contribute to symptoms of PCOS. It is difficult to disrupt this cycle, which is why treating PCOS can be challenging (NICHD).

Symptoms

The symptoms can vary from person to person. Some women have few or even no symptoms, and may not realize they have PCOS until they have trouble getting pregnant (MedlinePlus). The symptoms of PCOS may include (MedlinePlus):

• irregular or missed menstrual periods
• too much hair on the face, chest, stomach, or thighs
• obesity, weight gain, or trouble losing weight
• severe acne which may be hard to treat
• oily skin
• patches of thickened dark skin (called acanthosis nigricans)
• infertility

PCOS is one of the most common causes of infertility, but many women with PCOS can still get pregnant (MedlinePlus). Pregnant women who have PCOS are at higher risk for certain problems, such as miscarriage (NICHD).

Health problems linked to PCOS

PCOS is linked to many other health problems, including (MedlinePlus):

• insulin resistance, which can lead to prediabetes and type 2 diabetes
• heart disease: having PCOS increases your risk, and this risk goes up as you age
• high blood pressure
• high LDL ("bad") cholesterol and low HDL ("good") cholesterol, which increases your risk of heart disease
• endometrial hyperplasia, a condition in which the lining of your uterus becomes too thick, which can increase your risk for endometrial cancer, also called uterine cancer
• sleep apnea, a disorder that causes you to repeatedly stop breathing during sleep (see sleep apnea symptoms)
• depression and anxiety

NICHD adds some numbers. More than one-half of women with PCOS have insulin resistance, about 25% to 45% of women with PCOS have metabolic syndrome, and more than one-half of women with PCOS will have either type 2 diabetes or prediabetes before their early 40s (NICHD).

Although there are links between PCOS and these conditions, researchers do not know whether PCOS causes some of these problems, some of these problems cause PCOS, or other conditions cause both (MedlinePlus). Not everyone who has PCOS will have all these problems, but you and your health care provider may want to monitor your health for signs of them, so they can be treated early (MedlinePlus).

How PCOS is diagnosed

There is no specific test for PCOS. Your provider will do a physical exam and ask about your medical history and family health history, and may do a pelvic exam, a pelvic ultrasound, and blood tests, including tests to check your hormone levels (MedlinePlus).

NIDDK lists PCOS among the health problems that may lead to obesity or weight gain; see obesity risk factors (NIDDK).

Common questions

Does PCOS run in families?

Yes. PCOS tends to run in families, and research suggests there are 19 possible gene variants that can increase a person's risk of developing it (MedlinePlus) (NICHD).

Does PCOS raise the risk of diabetes?

PCOS is linked to insulin resistance, which can lead to prediabetes and type 2 diabetes (MedlinePlus). More than one-half of women with PCOS will have either type 2 diabetes or prediabetes before their early 40s (NICHD). You can check your own score with the type 2 diabetes risk test.

Does PCOS raise the risk of endometrial cancer?

PCOS is linked to endometrial hyperplasia, a thickening of the lining of the uterus that can increase your risk for endometrial cancer, also called uterine cancer (MedlinePlus).