What is Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS) is a common female disorder. PCOS is thought to be a complex genetic disease that is strongly influenced by the environment, although the exact cause is still unclear. PCOS consists of both hormonal and metabolic problems. PCOS has three key characteristics:

• Excess Androgen: androgens are a group of hormones, like testosterone, involved in reproduction and development.

• Anovulation: when the ovaries don’t properly release an egg and disrupt the menstrual cycle.

• Polycystic Ovaries: small bumps that accumulate on the outside of the ovaries. Despite the name, they are not actually cysts.

These characteristics lead to symptoms such as excess hair and irregular menstruation, as well as long term risks such as diabetes and cardiovascular disease.

More about PCOS symptoms, risks and diagnosis

On this page

• How Common is PCOS?

• PCOS and Insulin

• PCOS and Fat

• PCOS and Sex Hormones

• PCOS and Genetics

• PCOS and the Environment

PCOS is one of the most common human disorders and it is the most common hormonal disorder in women. The exact number of people with PCOS varies depending on what method is used to diagnose PCOS however most studies estimate that around 10% all reproductive-aged women have PCOS. Many women who have PCOS go undiagnosed.

Additionally, some women who do not suffer from PCOS may have disorders that increase their risk of developing PCOS. These risk factors include excess androgen levels (for example, excess hair growth or acne), menstrual dysfunction, insulin resistance, or a family history of PCOS.

Insulin is one of the most important drivers of PCOS and its symptoms. Insulin is an important hormone that has many roles in the body. The primary function of insulin is to tell the body to absorb sugar and store it as fat when blood sugar levels are high. Women who have PCOS are likely to develop insulin resistance. Around 50-70% of all women with PCOS will develop insulin resistance. Most PCOS sufferers will have an insulin resistance higher that that of somebody with the same Body Mass Index (BMI). Obesity dramatically increases insulin resistance. The actual mechanism of insulin resistance is still not very understood, but it is thought to be rooted in genetics.

In response to insulin resistance, the body will automatically produce excess insulin to properly regulate blood sugar. This excess insulin, called hyperinsulinemia, is what causes many of the symptoms of PCOS and can lead to long term health risks like Type II Diabetes.

Excess insulin sends many signals to the body that have very serious effects for PCOS sufferers:

• Disrupts the ovaries and prevents them from releasing an egg.

• Increases the amount of androgen hormones that the body produces.

For a complete guide on PCOS and Insulin, check out: PCOS, Insulin and Obesity: Everything you need to know

Excess body fat and obesity are heavily linked to PCOS. Importantly, high body fat can increase insulin resistance, however obesity is not essential to insulin resistance. Around 40-50% of PCOS sufferers are not obese but still suffer from insulin resistance. Women with PCOS tend to have problems with the way insulin communicates with tissue around the body, which results in excess testosterone. This problem may contribute to why obesity among women with PCOS is much higher than with women of the same age as them.

Fat is very important in the body and is responsible for sending signals that help to regulate metabolism, appetite, brain activity, digestion and inflammation! For women with PCOS, some of the signals from fat tissue are disrupted. This disruption increases the development of insulin resistance.

See: PCOS, Insulin and Obesity: Everything You Need to Know

Although the role of fat in PCOS is still not fully understood, it is clear that excess fat makes many of the symptoms of PCOS much worse and increases the risk of developing serious health problems, like Type II Diabetes and cardiovascular disease. More research into what goes wrong in the fat tissue of women with PCOS may lead to new treatments for PCOS but until then, managing bodyweight is one of the single best things you can do to treat your PCOS.

Gonadotropins are a family of hormones that are heavily involved in the regulation of ovary and testicle function. Gonadotropins are essential to proper growth, sexual development and reproduction. Two important gonadotropins are Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH).

About 70% of women with PCOS have increased Luteinizing Hormone levels. Luteinizing Hormone is normally responsible for the production of testosterone in the ovaries, which is then converted to hormones such as estrogen and progesterone. For people with PCOS, the ovaries do not properly convert the testosterone into estrogen and progesterone. Therefore, due to the high levels of Luteinizing Hormone and poor conversion to estrogen, the ovaries produce a high amount of testosterone.

Follicle Stimulating Hormone normally causes the ovaries to begin the process of ovulation. Follicle Stimulating Hormone must be present above a certain amount for the ovaries to begin ovulating. In women with PCOS, levels of Follicle Stimulating Hormone do not rise high enough to cause the ovaries to begin ovulating. Follicle Stimulating Hormone does not reach a sufficient level in women with PCOS because of the improper level of estrogen, which supresses Follicle Stimulating Hormone production. This is why treatments such as Clomiphene (which stops estrogen levels from supressing FSH) cause women with PCOS to ovulate and are used to treat PCOS infertility.

See: Ovulation, Menstruation and PCOS: What Goes Wrong?

PCOS is caused by a mixture of genetic factors and the environment, this is known as a complex genetic disease. Between 20-40% of immediate female relatives of PCOS sufferers will also have PCOS. This is much higher than the general population (around 10% of the general population has PCOS).

Studies using twins and family members suggest that there are genetic factors that influence PCOS. Excess androgen, insulin resistance and excess insulin production can all be inherited by families of PCOS sufferers. Even male relatives can inherit increased insulin resistance, metabolic syndrome and more.

Some genes have been found that contribute to the development of PCOS, but compared to similar diseases, like Type II Diabetes, progress has been very slow in this area.

Interestingly, PCOS is prevalent all around the world, which suggests that it is incredibly old and likely arose in the human population before it first migrated out of Africa. The fact that this genetic disorder has survived for so long in the population despite its negative downsides suggests that it actually gave families an evolutionary advantage that helped them survive! Excess testosterone made women stronger and faster whilst increased energy storage as fat due to insulin resistance allowed them to survive times of famine much better than their “healthy” peers.

PCOS is caused by a combination of genetic factors and environmental factors. Most importantly, PCOS is seriously affected by weight gain and obesity. Weight gain has been shown to worsen insulin resistance, menstrual problems and androgen excess. Women in the US tend to have worse PCOS symptoms as they, on average, have a greater body weight and higher dietary saturated fat intake. Losing weight has been shown to greatly improve androgen and insulin levels whilst also reducing excess hair growth and increasing the success of ovulation. Even moderate exercise without any fat loss has been shown to improve insulin resistance!

Environmental hormone disruption is another important factor for PCOS that may affect metabolic and ovary activity. Bisphenol A, commonly known as BPA, is found in some plastics. Studies in rats have shown that BPA enhances androgen production in females and causes insulin resistance! It is likely that hormone disruptors such as BPA will make PCOS symptoms worse.