COMSAE Endocrine and Reproductive Systems 1 — Questions and Answers
Question 1: A 45-year-old woman presents with weight gain, cold intolerance, constipation, and a TSH of 12 mIU/L with low free T4. Which is the most appropriate initial treatment?
- Levothyroxine (Correct answer)
- Liothyronine
- Methimazole
- Radioactive iodine
Correct answer: Levothyroxine
Levothyroxine (synthetic T4) is the first-line treatment for hypothyroidism due to its stable half-life and reliable conversion to active T3.
Question 2: On COMSAE, a patient with Cushing's syndrome undergoes an overnight dexamethasone suppression test. Which finding is most consistent with a pituitary ACTH-secreting adenoma (Cushing's disease)?
- Suppression with high-dose dexamethasone (Correct answer)
- No suppression with either dose
- Suppression with low-dose dexamethasone
- Undetectable ACTH levels
Correct answer: Suppression with high-dose dexamethasone
Pituitary Cushing's disease retains partial feedback sensitivity and suppresses cortisol with high-dose (but not low-dose) dexamethasone.
Question 3: A 28-year-old woman has oligomenorrhea, hirsutism, and an LH:FSH ratio of 3:1. Pelvic ultrasound shows bilateral ovarian cysts. Which is the most likely diagnosis?
- Polycystic ovary syndrome (PCOS) (Correct answer)
- Premature ovarian insufficiency
- Hypothyroidism
- Hyperprolactinemia
Correct answer: Polycystic ovary syndrome (PCOS)
PCOS is characterized by hyperandrogenism, oligoovulation, and polycystic ovaries, often with an elevated LH:FSH ratio.
Question 4: A patient with type 2 diabetes has an HbA1c of 9.2% despite lifestyle modification. Which medication class improves insulin sensitivity primarily in peripheral tissues?
- Thiazolidinediones (Correct answer)
- Sulfonylureas
- DPP-4 inhibitors
- Alpha-glucosidase inhibitors
Correct answer: Thiazolidinediones
Thiazolidinediones (e.g., pioglitazone) activate PPAR-gamma receptors, enhancing insulin sensitivity in muscle and adipose tissue.
Question 5: Which hormone is primarily responsible for stimulating milk ejection (let-down reflex) during breastfeeding?
- Oxytocin (Correct answer)
- Prolactin
- Estrogen
- Progesterone
Correct answer: Oxytocin
Oxytocin, released from the posterior pituitary in response to suckling, causes myoepithelial cell contraction and milk ejection.
Question 6: A 32-year-old man presents with bilateral gynecomastia, small firm testes, and infertility. Karyotype shows 47,XXY. Which of the following best describes this condition?
- Klinefelter syndrome (Correct answer)
- Turner syndrome
- Kallmann syndrome
- Androgen insensitivity syndrome
Correct answer: Klinefelter syndrome
Klinefelter syndrome (47,XXY) presents with hypogonadism, infertility, gynecomastia, and small firm testes due to seminiferous tubule dysgenesis.
COMSAE Endocrine and Reproductive Systems 1
A 45-year-old woman presents with weight gain, cold intolerance, constipation, and a TSH of 12 mIU/L with low free T4.
Which is the most appropriate initial treatment?