Polycystic Ovarian Syndrome Flashcards
What is PCOS and what are the characteristic features?
- a common condition causing metabolic + reproductive problems in women
- the characteristic features are:
- multiple ovarian cysts
- hyperandrogenism
- insulin resistance
- infertility
- oligomenorrhoea
What is meant by anovulation and oligoovulation?
anovulation:
- the absence of ovulation
oligoovulation:
- irregular, infrequent ovulation
What is meant by amenorrhoea and oligomenorrhoea?
amenorrhoea:
- the absence of menstrual periods
oligomenorrhoea:
- irregular, infrequent menstrual periods
What are the criteria used to diagnose PCOS?
Rotterdam criteria
a diagnosis requires at least 2 of the 3 key features
What features are included in the Rotterdam criteria?
oligoovulation / anovulation:
- presents with absent or irregular menstrual periods
hyperandrogenism:
- presents with hirsutism / acne
polycystic ovaries on US:
- presence of 12 or more follicles on a single ovary
- or an ovarian volume of > 10 cm3
at least 2 of the 3 criteria must be present for diagnosis
What are the typical presenting features of PCOS?
- oligomenorrhoea / amenorrhoea
- hirsuitism
- acne
- obesity
- infertility
- hair loss in a male pattern
around 70% patients with PCOS are obese
What is the most significant complication of PCOS and its implications?
- it is associated with insulin resistance + diabetes
- this may present with acanthosis nigricans
- increased risk of cardiovascular disease + hypercholesterolaemia
What is acanthosis nigricans?
- thickened, rough skin found in the axilla or on the elbows
- it can also occur on the neck
- skin has a velvety texture
- associated with insulin resistance
What are the other complications associated with PCOS?
- increased risk of endometrial hyperplasia + cancer
- obstructive sleep apnoea
- depression / anxiety
- sexual dysfunction
What medications can also cause hirsuitism?
- phenytoin
- ciclosporin
- corticosteroids
- testosterone
- anabolic steroids
What other conditions can cause hirsuitism?
- congenital adrenal hyperplasia
- Cushing’s syndrome
- ovarian / adrenal tumours secreting androgens
How does insulin resistance contribute to hyperandrogenism in PCOS?
- when there is insulin resistance, the pancreas has to produce more insulin to get a response from the cells of the body
- insulin promotes the release of androgens from the ovaries / adrenal glands
!! higher levels of insulin = higher levels of androgens !!
In what other way can insulin resistance contribute to hyperandrogenism in PCOS?
- insulin suppresses sex hormone-binding globulin (SHBG) production by the liver
- SHBG binds to androgens and suppresses them
- reduced SHBG further promotes hyperandrogenism
How does insulin resistance affect the formation of polycystic ovaries?
- high levels of insulin contribute to halting the development of follicles in the ovaries
- this results in anovulation
- and the presence of multiple partially developed follicles
- the partially developed follicles are seen as polycystic ovaries on US
What blood tests are required to diagnose PCOS and exclude other pathology that presents similarly?
- testosterone
- sex hormone-binding globulin (SHBG)
- lutenising hormone (LH)
- follicle stimulation hormone (FSH)
- prolactin
- thyroid-stimulating hormone (TSH)
prolactin may be mildly raised in PCOS
What blood test results would you expect to see in PCOS?
- raised LH
- raised LH to FSH ratio
- raised testosterone
- raised insulin
- normal / raised oestrogen
Following hormonal blood tests, what investigation is performed in suspected PCOS?
pelvic / transvaginal USS
this is NOT reliable in diagnosing PCOS in adolescents
What is the traditional appearance of PCOS on transvaginal US?
- the follicles are arranged around the periphery of the ovary
- this gives a “string of pearls” appearance
How is transvaginal US used to diagnose PCOS?
- 12 or more developing follicles in ONE ovary
OR
- ovarian volume of > 10cm3
increased ovarian volume can indicate PCOS even in the absence of cysts
How is diabetes screened for in patients with PCOS?
oral glucose tolerance test (OGTT)
What is involved in the OGTT?
- this is performed in the morning prior to breakfast
- the patient is given a 75g oral glucose drink
- a fasting plasma glucose and a plasma glucose 2 hours later are meaasured
What results of the OGTT suggest the presence of diabetes?
plasma glucose > 11.1 mmol/l 2 hours after the glucose drink
if plasma glucose is 7.8 - 11.1 mmol/l 2 hours after the drink, this suggests impaired glucose tolerance
What advice is given to patients with PCOS to reduce the risks associated with obesity / diabetes?
- weight loss
- calorie-controlled diet
- exercise
- smoking cessation
- antihypertensive medications if indicated
- statins where QRISK > 10%
What is the most significant lifestyle modification important in the treatment of PCOS?
weight loss
- this can restore fertility + regular menstruation by allowing ovulation
- improvement in insulin resistance + hyperandrogenism
- reduces risk of diabetes, CVD + hypercholesterolaemia
