Endocrinology: insulin and lipolysis: 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: insulin and lipolysis

Sample item

A patient with untreated type 1 diabetes has high circulating free fatty acids. Which change in adipose tissue explains the excessive lipolysis?

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

The answer and the reasoning

A. Loss of insulin inhibition of hormone-sensitive lipase

Insulin suppresses hormone-sensitive lipase and promotes triglyceride storage. With insulin deficiency this enzyme is disinhibited and lipolysis releases large amounts of free fatty acids and glycerol, which feed hepatic ketone production.

Option by option

  • A. Loss of insulin inhibition of hormone-sensitive lipase (correct)

    Correct. Without insulin, hormone-sensitive lipase is disinhibited and free fatty acids pour out.

  • B. Increased esterification of fatty acids to triglyceride

    Insulin promotes esterification, so in deficiency it falls rather than rises.

  • C. Reduced catecholamine action on adipocytes

    Catecholamine action promotes lipolysis and is not reduced in this setting.

  • D. Increased activity of lipoprotein lipase in adipose tissue

    Lipoprotein lipase in adipose tissue is stimulated by insulin and would be reduced, not raised.

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 A, Loss of insulin inhibition of hormone-sensitive lipase. Insulin suppresses hormone-sensitive lipase and promotes triglyceride storage.

Why is "Increased esterification of fatty acids to triglyceride" not the answer?

Insulin promotes esterification, so in deficiency it falls rather than rises.

Why is "Reduced catecholamine action on adipocytes" not the answer?

Catecholamine action promotes lipolysis and is not reduced in this setting.

Why is "Increased activity of lipoprotein lipase in adipose tissue" not the answer?

Lipoprotein lipase in adipose tissue is stimulated by insulin and would be reduced, not raised.

What concept does this question test?

It tests Endocrinology: insulin and lipolysis in Physiology. With insulin deficiency this enzyme is disinhibited and lipolysis releases large amounts of free fatty acids and glycerol, which feed hepatic ketone production.

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: insulin and lipolysis?

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.