Blood glucose is a term that describes the amount of sugar, or glucose, that enters your bloodstream from the various foods in your diet. Persistent high levels of glucose in your blood can expose you to serious health risks from a condition called diabetes. Your body responds to blood glucose elevations with insulin, a hormone secreted by your pancreas.
Pancreas Basics
Your pancreas is a gland located between your spine and stomach, in an area just below your liver. Between 90 and 95 percent of pancreatic tissues produce digestive enzymes, substances that help you process food in your small intestine, Endocrine Web reports. The remaining five percent of the pancreas produces insulin and other vital hormones---including glucagon, gastrin and somatostatin---which pass directly from your pancreas to your bloodstream. The cells that produce these hormones are called the pancreatic islet cells.
Insulin Release
When your blood glucose levels rise, your pancreas releases insulin. In turn, the presence of insulin activates certain receptors in cells throughout your body, including those contained in fat and muscle tissue. These receptors act as gateways, and under insulin's influence, they open and allow glucose from your bloodstream to enter your cell's interiors. Once inside your cells, glucose acts as a primary energy source for various cellular functions. Certain cells in your body, including those found in your brain, do not require the presence of insulin to access your available glucose.
Liver Effects
Insulin also signals your liver to remove excess glucose from your bloodstream, Colorado State reports. Inside your liver, this glucose is converted to a related substance called glycogen and held for future use. In addition to sending general signals to your liver, insulin directly triggers glycogen conversion by activating certain liver enzymes responsible for glycogen production. The general effect of insulin's interactions with your fat, muscle and liver cells is a decrease in your blood glucose that typically keeps your glucose levels within a healthy range.
Insulin Resistance
In some circumstances, your liver, fat and muscle cells can fail to respond properly to insulin's effects, according to the National Diabetes Information Clearinghouse, or NDIC. If this occurs, your pancreas will attempt to increase insulin production in order to maintain normal glucose control. In time, your pancreas can fail at this task, leading to an unwanted buildup of glucose in your bloodstream. The result of this process of insulin desensitization is called insulin resistance. The development of insulin resistance significantly raises your risks for the development of type 2 diabetes and heart disease.
Considerations
The NDIC lists factors in the development of insulin resistance and diabetes that include lack of exercise, excessive body weight and genetic predisposition. If you have insulin resistance, you may also have other known risk factors for diabetes and heart disease, including high cholesterol and triglycerides, high blood pressure and excessive weight centered on your abdomen or belly. If you have a combination of these factors, you have an additional risk for serious disease called metabolic syndrome.
References
- Discovery Health: How Diabetes Works (Pages 1 and 2)
- National Diabetes Information Clearinghouse: Insulin Resistance and Pre-Diabetes
- American Association for Clinical Chemistry - Lab Tests Online: Diseases of the Pancreas
- EndocrineWeb: Endocrine Tumors of the Pancreas; A Guide to Insulin, Glucagon, Somatostatin and Gastrin
- Colorado State University: Physiologic Effects of insulin
