Digestive Hormone That Spikes When Asleep

This page is the CodyCross answer for the clue below from Comics, Group 1077, Puzzle 4 (Subscription Fold).

Question is: Digestive Hormone That Spikes When Asleep

and the answer is: LEPTIN

Word Meaning:

LEPTIN — (biochemistry) A protein hormone produced in adipose tissue; it plays a role in regulating appetite and metabolism.

Definitions from Wiktionary.