The Glucose-Insulin System
By Dr Joseph J Collins, ND, RN
This article is part of the Blood Sugar Health Educational Module
Having a good understanding of the GIS will help you understand how you can control your blood sugar levels by supporting ideal function of the GIS. Your Glucose-Insulin-System is a dynamically active system in which insulin levels and glucose levels are maintained within a very narrow ideal range by feedback between glucose levels and insulin levels with various tissues in the body.
The GIS is one of the homeostasis regulatory systems that has a profound effect on metabolism. Metabolism is all the chemical processes in an organism by which its material substance is produced, maintained, and destroyed, and by which energy is made available. Metabolism can be divided into two major processes; anabolism and catabolism. Anabolism involves the uptake and storage of substances, which are anabolic processes that are also called constructive metabolism. Catabolism involves the breakdown of substances, which are moved out of storage, which are catabolic processes that are also called destructive metabolism.
Anabolism may be described as synthesis of complex molecules in living organisms from simpler ones, resulting in the storage of energy. Catabolism may be described as the breakdown of complex molecules in living organisms to form simpler ones, resulting in the release of energy.
As you might imagine, the Glucose-Insulin-System (GIS) is a homeostasis regulatory system that has been the subject of tremendous amounts of research. It is believed that by understanding the complex intricacies of this system, that the epidemic of prediabetes and diabetes can be controlled.
Your pancreas, liver, muscles and fat cells work together to maintain glucose levels within the ideal range. The pancreas is an organ that is part of the digestive system as well as part of the endocrine system. As a part of the digestive system, the pancreas secretes bicarbonate which neutralizes acid entering the small intestine from the stomach. It also secretes digestive enzymes, which break down carbohydrates, proteins, and fats in food entering the small intestine from the stomach.
The endocrine component of the pancreas is contained within regions of the pancreas called pancreatic islets of islets of Langerhans. When blood sugar levels are increased, beta cells within the pancreatic islets secrete insulin. On the other hand, when blood sugar levels are decreased, alpha cells secrete glucagon. Insulin and glucagon are the two major hormones that affect blood sugar levels.
Delta cells secrete somatostatin which regulates the production and function of insulin and glucagon. Epsilon cells produce ghrelin which affects feelings of hunger, and pancreatic polypeptide cells (PP cells) produce pancreatic polypeptide, which regulates pancreatic and gastrointestinal secretions and functions.
Insulin is the primary hormone that lowers blood glucose by increasing glucose uptake and utilization by your liver, muscles and fat cells. When your blood glucose gets too high, beta-cells in your pancreas secrete more insulin, which makes your liver and muscles store the excessive glucose by converting it to glycogen, which is one of the ways that the body stores extra glucose. Glycogen is made up of glucose molecules branched together to store glucose for later use, and stored primarily in the liver and skeletal muscles, with some stored in the heart, brain and other tissues. The other way the body stores extra glucose is by converting into triglycerides, which are stored in fat cells, as adipose tissue.
In addition to affecting blood glucose levels, the Glucose-Insulin-System (GSI) also affects the metabolism of fatty acids, which can be converted into triglycerides and stored as fat in adipose tissue. Insulin and glucagon have opposing and balancing effects on the metabolism of carbohydrates, fatty acids and amino acids.
Insulin affects carbohydrate, fatty acid and amino acid metabolism.
- Insulin stimulates the synthesis of glycogen by the uptake and storage of extra glucose, in a process called glycogenesis. In addition to increasing glycogen storage, insulin also prevents the breakdown of glycogen by inhibiting glycogenolysis.
- Insulin causes fat cells to uptake glucose and converts excess glucose into fat through a process called fatty acid synthesis. Fatty acids are then converted into triglycerides and stored in adipose tissue as fat.
- Insulin forces cells to absorb circulating amino acids and decreases the breakdown of proteins
- Glucagon affects carbohydrate, fatty acid and amino acid metabolism.
- Glucagon stimulates the breakdown of glycogen (stored carbohydrates) to be released into the blood as glucose, which is a process called glycogenolysis.
- Glucagon stimulates the breakdown stored fat (triglycerides) into fatty acids for use as fuel by cells (lipolysis).
- Glucagon stimulates the breakdown and conversion of amino acids into glucose, in a process called gluconeogenesis.
This opposing effect is most notable in the effect that insulin has on the ability of glucagon to break down glycogen and turn it back into glucose. As noted, the conversion of glycogen back into glucose is a process called glycogenolysis. Glycogenolysis is required to maintain adequate blood sugar levels in between meals. If glycogenolysis does not take place, and the body is not able to add more glucose into the blood, then hypoglycemia (low blood sugar) will be the result.
While it is well-known that people who are taking insulin injections are at risk of developing hypoglycemia, it is also important to note that people who have insulin resistance / prediabetes are also at risk for having episodes of hypoglycemia.
In insulin resistance, the increased insulin levels in the blood have an adverse effect on glycogenolysis and decrease the ability of the body to break down glycogen and add glucose back into the blood stream. As a result, people with prediabetes (insulin resistance) actually have episodes of low blood sugar (hypoglycemia).
Specific herbs in GlucoQuench™ have been shown to support the function of each of the various organs and cells of the Glucose-Insulin System. GlucoQuench™ contains herbs that can support the functions of the Glucose-Insulin System.