Polycystic Ovary Syndrome (PCOS) is caused by the imbalance of hormones. It is a common heterogenous disease. This means that many women can have a variety of different symptoms. You're not alone, around 6-12% of women are diagnosed with PCOS.
The symptoms of the PCOS include:
Reproductive problems
Excessive hair growth
Mood changes
Weight changes and trouble losing weight
Ovarian cysts
Low sex drive
Acne
Fatigue
High testosterone levels
Male patterns of baldness
PCOS women have two main things in common.
Firstly, all PCOS women have two out of the three symptoms of the "Rotterdam Criteria". This is how PCOS is diagnosed clinically.
"What is the Rotterdam Criteria?"
Polycystic ovaries
"What are polycystic ovaries?"
Polycystic ovaries are ovaries which contain many fluid-filled follicles that surround an egg. These follicles are arrested in their maturation (folliculogenesis). This prevents their selection for ovulation. The arrest in their maturation is caused by hormone imbalances.
Polycystic ovaries are diagnosed by a pelvic or a transvaginal ultrasound. Here is an image of polycystic ovaries on an ultrasound, where the black "blobs" present a cyst.
Polycystic ovaries are caused by abnormal hormone stimulation. However, it is important to understand that you do not need polycystic ovaries to be diagnosed with PCOS.
Hyperandrogenism
"What is meant by hyperandrogenism?"
Hyperandrogenism is the excessive levels of circulating male sex hormones (also referred to as androgens) in women. An example of a male sex hormone elevated in PCOS is testosterone.
This excess of circulating androgens can be produced by the ovaries or the adrenal gland (adrenal PCOS).
In the ovary, abnormal hormone stimulation on ovarian follicles triggers the extreme production of testosterone. This disrupts follicle development required for ovulation.
High testosterone levels can affect ovulation, but can also cause male characteristics such as: hirsutism (excessive facial hair growth), acne and balding.
Anovulation
"What is meant by anovulation?"
The lack or absence of ovulation as a result of abnormal hormone stimulation which can lead to infertility.
So to conclude, the three symptoms of the Rotterdam Criteria are: polycystic ovaries, hyperandrogenism and anovulation.
Secondly, all PCOS women have an increase in the circulating levels of Luteinizing Hormone (LH).
"What is LH?"
LH is a hormone secreted from the brain, specifically an area called the anterior pituitary. It is a hormone that should be measured in a blood test when clinically diagnosing PCOS.
LH has an essential role in the development and maturation of ovarian follicles. Ovarian follicles surround an egg which maturation is required for ovulation.
LH acts on ovarian theca cells, which are the outer layer of cells of developing follicles. This causes the production of an androgen substrate (for example, testosterone) for estrodial synthesis.
However, excessive LH stimulation on these ovarian theca cells produces an abnormal amount of androgens (testosterone). This produces a special microenvironment that reduces granulosa cell (the inner layer of cells), sensitivity to Follicle Stimulating Hormone (FSH). This is responsible for producing estrodial from testosterone.
Therefore, the high levels of testosterone produced by ovarian theca cells are not eliminated. This disrupts folliculogenesis and causing symptoms of high testosterone.
So put simply, abnormal LH action on ovarian follicles causes too much testosterone to be produced. This prevents their maturation for ovulation.
The diagram below presents this process described above. The blue arrows show what is elevated and declined in PCOS to disrupt ovulation.
This probably seems confusing. So to understand this further please read my blog: "What is the process to ovulation and how is it disrupted in PCOS?"
Komentarze