Gynaecological endocrinology: SHBG and free testosterone: practice question

A OBG question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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OBG · Gynaecological endocrinology: SHBG and free testosterone

Sample item

An obese woman with PCOS has severe hirsutism although her total testosterone is only mildly raised. What best explains this?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Hyperinsulinaemia lowers SHBG, so free testosterone rises

Insulin suppresses hepatic synthesis of sex hormone binding globulin. Less binding protein leaves a larger free, active fraction of testosterone, so clinical hirsutism may be marked despite a modest total value.

Option by option

  • A. Leptin raises SHBG and frees dihydrotestosterone

    Leptin does not raise SHBG, and a rise would lower free testosterone.

  • B. Hyperinsulinaemia lowers SHBG, so free testosterone rises (correct)

    Correct. Low SHBG increases the free, biologically active testosterone.

  • C. Insulin increases renal clearance of androgens

    Insulin does not raise renal androgen clearance.

  • D. LH converts testosterone to oestradiol in blood

    Conversion of testosterone to oestradiol occurs through aromatase in tissues, not through LH in blood.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this OBG question

What is the answer to this OBG question?

The best answer is B, Hyperinsulinaemia lowers SHBG, so free testosterone rises. Insulin suppresses hepatic synthesis of sex hormone binding globulin.

Why is "Leptin raises SHBG and frees dihydrotestosterone" not the answer?

Leptin does not raise SHBG, and a rise would lower free testosterone.

Why is "Insulin increases renal clearance of androgens" not the answer?

Insulin does not raise renal androgen clearance.

Why is "LH converts testosterone to oestradiol in blood" not the answer?

Conversion of testosterone to oestradiol occurs through aromatase in tissues, not through LH in blood.

What concept does this question test?

It tests Gynaecological endocrinology: SHBG and free testosterone in OBG. Less binding protein leaves a larger free, active fraction of testosterone, so clinical hirsutism may be marked despite a modest total value.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Gynaecological endocrinology: SHBG and free testosterone?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.