Table 1.

Appetite-related hormones and adipocytokines that are estimated to be affected by hypoxic conditions

Hormone or adipocytokine	Function
GLP-1 (↑)	GLP-1 is thought promote satiety through several mechanisms, including slowing gastric emptying and enhancing insulin biosynthesis and secretion. Also, it decreases blood sugar levels in a glucose-dependent manner by enhancing the secretion of insulin.
Ghrelin (↓)	The hunger hormone ghrelin is a peptide hormone produced by ghrelinergic cells in the gastrointestinal tract that functions as a neuropeptide in the central nervous system and plays an important role in regulating the distribution and rate of use of energy.
Leptin (↑)	The hormone of energy expenditure leptin is a hormone predominantly made by adipose cells that helps to regulate energy balance by inhibiting hunger. Leptin is opposed by the actions of the hormone ghrelin and both hormones act on receptors in the arcuate nucleus of the hypothalamus to regulate appetite to achieve energy homeostasis.
PP (↑)	PP is a polypeptide secreted by PP cells in the endocrine pancreas predominantly in the head of the pancreas and it functions to self-regulate pancreatic secretion activities (endocrine and exocrine); it also has effects on hepatic glycogen levels and gastrointestinal secretions. PP has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa.
PYY (↑)	PYY inhibits gastric motility and increases water and electrolyte absorption in the colon. It may also suppress pancreatic secretion and has been shown to reduce appetite. PYY works by slowing gastric emptying; hence, it increases efficiency of digestion and nutrient absorption after a meal.

↑, increased secretion response by hypoxic condition; ↓, decreased secretion response by hypoxic condition; GLP-1, glucagon-like peptide-1; PP, pancreatic polypeptide; PYY, peptide YY.