Lecture 18: Polycystic Ovary Syndrome Pathophysiology

Question 1

What did polycystic ovary syndrome used to be called?

Answer 1

Stein-Leventhal Syndrome

Question 2

What is the definition of polycystic ovary syndrome?

Answer 2

PCOS is an ANDROGEN excess disordeer
1. Clinical or biochemical HYPERandrogenemia
2. Chronic oligomenorrhea or anovulation
3. Exclusion of related disorders (pituitary, adrenals, ovary)
Also, polycystic ovaries on ultrasound

Question 3

How does hyperandrogenism present?

Answer 3

1. Hirsutism

2. hyperandrogenemia (free T)

Question 4

Why is PCOS called polyscystic ovary?

Answer 4

A shitload of follicles in the ovary
LOOKS LIKE cysts but they are really follicles
Arrested follicular growth
Each follicle has an egg in it

Question 5

What is the differential for a woman with oligoovulation and/or anovulation?

Answer 5

1. HYPOthyroidism
2. HYPERprolactinemia
3. PCOS

Question 6

What are clinical symptoms of hyperandrogenism?

Answer 6

1. Less than 6-9 menses per year
2. low mid luteal progesterone levels
3. hirsutism
4. acne
5. male pattern balding
6. Insulin resistance

Question 7

Is obesity part of the diagnosis of PCOS?

Answer 7

Obesity is NOT a diagnosis of PCOS

Question 8

How do you diagnose PCOS?

Answer 8

Look for free T
Look at clinical symptoms of anovulation/oligoovulation
Hirsutism, acne, balding
One ovary with 12 or more follicles measuring 2mm in diameter

Question 9

What are the consequences of FSH sensitivity of follicles in PCOS patients?

Answer 9

Above graph shows that in PCOS females, ALL FOLLICLES are sensitive to FSH so there is more than one follicle that is growing.
In normal women, one follicle grows predominately

Question 10

What is a hypothalamic/pituitary characteristic of PCOS?

Answer 10

There is erratic GnRH secretion and therefore erratic LH secretion
More LH than FSH secreted
Decreased sensitivity with estradiol/progesterone

Question 11

What is the response of ovary in PCOS?

Answer 11

Granulosa cell Sensitivity to FSH is increased

Increased density of small pre-antral follicles in PCOS

Question 12

What is the relation between insulin and PCOS?

Answer 12

Insulin resistance, manifested by
1. acanthosis nigricans
2. Insulin resistance in muscle, adipose tissue and liver
3. insulin increases ovarian androgen production!!
Postreceptor mechanism (no structural abnormality except for post receptor defect)

Question 13

What is the significance of acanthosis nigricans?

Answer 13

Marker of insulin resistance

Associated with PCOS

Question 14

How do you treat PCOS?

Answer 14

OCPs
Anti-androgens
Weight loss and insulin sensitizing agents