Evidence
Hormone and Peptide Theory
Three principle messengers have been implicated in the success of weight loss surgery to cure diabetes:
- Ghrelin
- Glucagon like peptide
- Peptide YY
Ghrelin is produced by the body of the stomach. It is a messenger for hunger. Levels rise when hungry and fall after eating. Reducing the size of the stomach causes a consequential fall in levels of ghrelin. The person feels less hungry and more satiated with smaller meals.
Glucagon like peptide (GLP) is a messenger produced by the pancreas. It is produced in response to food entering the small bowel. It has several effects which are beneficial to diabetic patients:
- Increasing insulin secretion from the pancreas
- Decreasing glucagon secretion from the pancreas
- Increasing beta cells mass in the pancreas
- Inhibiting acid secretion in the stomach
- Decreasing food intake by increasing satiety
The net effect is the restoration of glucose metabolism in the body.
Peptide YY (PYY) is a messenger which reduces appetite. It is produced by cells in the terminal ileum in response to the presence of food. In obese individuals the levels of PYY are lower than in their non obese counterparts.
The ideal treatment of Type 2 diabetes would elevate ghrelin, increase GLP and increase PYY.
It would not be a surprise that gastric bypass surgery achieves all these aims.