What is leading to rising cases of PCOS?

1 in 5 women in the country today are dealing with Polycystic Ovary Syndrome (PCOS) and several more remain undiagnosed. PCOS is a condition in which women experience irregular or missed periods, ovaries with cysts, acne, weight gain or excessive hair growth and difficulty in getting pregnant

To understand PCOS, we need to understand what typically happens in a normal menstrual cycle. Typically, the menstrual cycle starts with pituitary gland in brain releasing Follicle Stimulating Hormone (FSH). This is also known as the follicular phase. Inside their ovaries, women carry thousands of immature eggs and FSH acts as a stimulant signalling a small group of them to grow.

As these follicles grow, they start producing estrogen and usually one follicle becomes a dominant follicle growing faster than others and pumps out more and more estrogen signalling the brain to stop FSH; essentially leading to death of other small follicles.

The rising estrogen in the dominant follicle signals the brain to release another hormone called LH (Luteinizing Hormone). The surge in LH, causes the wall of the dominant follicle to rupture which leads to egg getting released in the fallopian tube where it waits for next 24-48 hours to get fertilized. This is the ovulation phase. The shell that remains after release of the egg, then absorbs cholesterol from the blood stream and converts into something called as corpus luteum, which is essentially a progesterone factory. After about 7 days of ovulation, progesterone reaches its peak. If there is no conception, the corpus luteum begins to wither away, progesterone collapses and uterine lining sheds which is essentially what causes the period. This entire period from the start release of egg until the period starts is the luteal phase. High progesterone also signals to brain to stop producing LH and the cycle starts over again.

In a patient with PCOS, the brain keeps sending LH all the time. Because LH is high all the time and FSH is 'relatively low', no dominant follicle develops. So you see partially grown follicles that never release their eggs. Since no egg ever is released, no corpus luteum is formed, progesterone does not increase and brain does not get the signal to stop producing LH and LH levels do not drop. The body is stuck in a pre-ovulation phase. 

One of the reason body gets stuck in high LH phase is high androgens (male hormone) such as testesterone. There are specialised cells in the ovaries which produce male hormones and they get activated if LH is high continuously. This process is often accelerated by the presence of high insulin which supports the growth of androgens. 

How do you know if you have PCOS? Firstly, do not ignore the symptoms mentioned at the start of the article. 3 simple blood test markers can help in diagnosing if you have PCOS:

Get your androgens checked with a marker called as Free Androgen Index (FAI) which is a ratio of total testosterone to your Sex Hormone Binding Globulin (SHBG) - a protein released by liver which prevents the control of testosterone. 

Second marker is Anti Mullerian Hormone (AMH) which is a protein hormone in the ovaries and makes the follicles less sensitive to FSH. In a typical cycle, AMH levels drop and that allows a dominant follicle to grow. In PCOS, given there are too many 'stuck' follicles, which implies AMH is high and no follicle ends up becoming dominant.

A third important marker increasingly is fasting insulin given the role insulin plays in growth of androgens (male hormones) which is the underlying issue in PCOS.

Source: 

National Library of Medicine, National Institute of Health (US)