The Role of Hormones in Polycystic Ovarian Syndrome (PCOS)

What is a Hormone?

Polycystic ovarian syndrome or PCOS, for short, is an endocrine condition, meaning that it is associated with issues related to hormones¹. Hormones are messengers produced by various parts of the body, like the brain, ovaries, and testes, which move to different areas of the body to deliver their message². This message results in some action being performed within the body². Hormones are also specific to the part of the body they are meant to act on, acting like keys that fit into specific locks, called receptors, that sit on the outside of cells².

An example of this is adrenaline³. Adrenaline is first released by the adrenal glands which sit on top of your kidneys, and it travels through the bloodstream to your heart, where these messengers fit into special locks called Beta receptors³. When this connection happens, the heart is told to beat faster, and it does exactly that³.

Biological females and biological males have the same sex hormones, just in different amounts⁴. Biological females have higher amounts of estrogen and progesterone, while biological males have higher amounts of testosterone⁴.

What do hormones normally do in the Female body?

Hormones work in teams to send certain messages and get work done. In the female body, the estrogen hormones—estradiol, estriol, estrone, and esterol—work to regulate ovulation⁵. Estradiol, as the strongest, is the most common in women of childbearing age⁴.

During the menstrual cycle, the pituitary gland in your brain sends messages to a few eggs in the ovaries through Follicle Stimulating Hormone (FSH) and luteinizing hormone (LH), which ultimately leads to the release of an egg in ovulation⁶. Prior to and following ovulation, estrogen and progesterone are sent from the ovaries to the uterus and nearby blood vessels to build and develop the uterine lining⁶. When pregnancy does not occur, a decrease in estrogen and progesterone leads to the breakdown of this lining, causing menstruation⁶.

Estrogen also plays a major role in skeletal, cardiovascular, and central nervous system health⁷. It impacts important bodily functions including blood sugar levels, cholesterol levels, bone and muscle mass, and brain function⁷. Too little estrogen can lead to dysfunction and dysregulation of these areas. Sometimes with PCOS, estrogen levels are too high in relation to progesterone levels, causing symptoms like heavy periods⁷.

Progesterone plays a major role in the development and maintenance of the uterine lining⁸. In the menstrual cycle, a decrease of progesterone leads to the shedding of the lining in menstruation⁸. In pregnancy, progesterone levels must remain high to maintain the uterine lining for the embryo⁸. If progesterone levels are too low, miscarriage, decreased fertility, and early labor may occur⁸.

Androgens—“male sex hormones” like testosterone—are produced in the female body fairly equally between the adrenal glands and the ovaries⁹. In women, androgens like testosterone are converted into estradiol¹⁰. However, androgens themselves aid in muscle development, bone density, and sexual desire¹⁰.

Hyperandrogenism and Insulin Resistance

Major symptoms of PCOS occur when there are the wrong amounts of the male messengers¹¹. When there is too much of the messenger testosterone, the result is a condition called hyperandrogenism¹¹. This imbalance causes symptoms we often associate with PCOS, such as acne, overly oily skin, excessive body hair—especially on the face, chest, and back—irregular periods, and male-pattern baldness¹¹. Approximately 80–90% of females with hyperandrogenism have PCOS, and many healthcare professionals attribute PCOS as the most common cause of this condition¹¹.

Insulin acts as a messenger from the pancreas that tells cells to let in glucose (sugar) from the bloodstream to use in energy production¹². Insulin resistance, found in 60–70% of women with PCOS, is a condition where the cells don’t listen to insulin¹². When this happens, cells do not accept sugar as effectively, and the body thinks there must not be enough insulin in the bloodstream¹³. It responds by releasing more insulin from the pancreas, which creates a buildup of insulin called hyperinsulinemia¹³.

The exact mechanisms connecting hyperinsulinemia and hyperandrogenism are still unknown, but the two conditions have demonstrated a strong correlation, suggesting that one hormone directly impacts the other¹⁴. Insulin has been found to prevent the liver from releasing a messenger called sex hormone binding globulin (SHBG), which regulates the amounts of androgens and estrogens in the body by holding onto them and deactivating them¹⁴. Too much insulin may overwhelm the liver, preventing SHBG from being released to perform its ability to regulate androgens, leading to high androgen levels in the body¹⁴. These high androgens then go on to cause the symptoms of PCOS discussed above¹⁴.

Conclusion

PCOS is associated with imbalances in various hormones, causing symptoms or directly driving imbalances in others. The hope is that through reading this article, you were able to learn something new about the amazing messengers that control our bodies, as well as what happens when they aren’t able to work properly. Understanding the molecular processes behind symptoms is crucial to understanding why certain symptoms arise and can offer a starting point for research, treatment, and management.