Endocrinology: thyroid hormone and lipids: practice question

A Physiology 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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Physiology · Endocrinology: thyroid hormone and lipids

Sample item

A 45-year-old woman with fatigue and cold intolerance has a raised TSH and low free T4. Her LDL cholesterol is also raised. Why?

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

The answer and the reasoning

C. Fewer hepatic LDL receptors slow the clearance of LDL from plasma

Thyroid hormone increases hepatic LDL receptor expression and cholesterol clearance. In hypothyroidism the receptors fall, so LDL stays longer in plasma and cholesterol rises. Treatment with thyroxine usually lowers LDL.

Option by option

  • A. Excess lipolysis releases cholesterol into the circulation

    Lipolysis is reduced rather than increased in hypothyroidism, and it would not raise LDL in this way.

  • B. Increased intestinal absorption of cholesterol driven by TSH

    TSH does not drive intestinal absorption of cholesterol.

  • C. Fewer hepatic LDL receptors slow the clearance of LDL from plasma (correct)

    Correct. Lower LDL receptor expression reduces LDL clearance, raising plasma LDL.

  • D. Reduced hepatic cholesterol synthesis

    Reduced synthesis would lower cholesterol, whereas the raised LDL results from poor clearance.

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 Physiology question

What is the answer to this Physiology question?

The best answer is C, Fewer hepatic LDL receptors slow the clearance of LDL from plasma. Thyroid hormone increases hepatic LDL receptor expression and cholesterol clearance.

Why is "Excess lipolysis releases cholesterol into the circulation" not the answer?

Lipolysis is reduced rather than increased in hypothyroidism, and it would not raise LDL in this way.

Why is "Increased intestinal absorption of cholesterol driven by TSH" not the answer?

TSH does not drive intestinal absorption of cholesterol.

Why is "Reduced hepatic cholesterol synthesis" not the answer?

Reduced synthesis would lower cholesterol, whereas the raised LDL results from poor clearance.

What concept does this question test?

It tests Endocrinology: thyroid hormone and lipids in Physiology. In hypothyroidism the receptors fall, so LDL stays longer in plasma and cholesterol rises. Treatment with thyroxine usually lowers LDL.

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 Endocrinology: thyroid hormone and lipids?

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology 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.