The body needs sources of energy in order to perform work and survive. Oxygen and the blood sugar glucose are important sources of energy. Blood sugar is regulated within narrow limits to maintain health. High or low blood sugar, known respectively as hyperglycemia and hypoglycemia, can be bad for the health and even dangerous. The hormone insulin plays an important role in the regulation of blood sugar. The diagnosis and treatment of disease should be made with the consultation of a health care professional.
Glucose Levels
Glucose is the main sugar found in blood. It is derived from carbohydrates in the diet. Glucose is a primary staple of energy for cells. Cells are able to break down glucose and use the energy stored in it to make ATP, the primary energy carrier of cells. Glucose alone can provide ATP, but much more can be created in the presence of oxygen. Glucose levels in the blood are regulated to supply a steady stream to the cells. If excess glucose enters the body, it can be stored as glycogen, a large chain of glucose found mostly in the liver and muscle, or converted into other compounds such as fat. Many factors regulate glucose levels, such as insulin.
Insulin
Insulin is a hormone released by the pancreas in response to a meal. Insulin is a protein hormone that signals cells to take up glucose. The hormone also has broader effects on overall metabolism as well as specific actions on cells. It changes the actions of numerous enzymes and increases DNA replication and protein synthesis. It increases glycogen and fatty acid synthesis and amino acid uptake, and decreases the breakdown of fats and proteins. In addition it increases stomach acid, potassium uptake by cells and relaxes arteries to increase blood flow.
Hyperglycemia
Hyperglycemia is caused by several conditions, typically a form of diabetes mellitus. In type I diabetes the pancreas fails to make insulin. In type II diabetes, the cells fail to respond to insulin. Some drugs and stress can also increase glucose levels. Acutely, elevated glucose levels are usually asymptomatic until they become very high. They can cause increased urination, thirst, hunger, blurred vision, dry mouth, confusion and coma. Chronically high glucose damages the blood vessels and can lead to heart attacks, stroke, kidney damage and failure, vision problems, poor circulation to the arms and legs requiring amputation, weakness of the immune system with chronic infections, among other problems.
Treatment of Hyperglycemia
The treatment of hyperglycemia depends on the cause. Very high glucose levels may require intravenous fluids and insulin. Type I diabetes is treated with insulin. Insulin is given by needle because it is a protein; if it is ingested it will be broken down by the stomach. Type II diabetes is associated with weight gain. It is treated with lifestyle changes such as diet and exercise. In addition, medications can be given to lower the blood glucose level, including insulin.
References
- "Physiology"; Linda S.Costanzo; 4th Ed 2008
- "Harrison's Principles of Internal Medicine"; Anthony S Fauci et al.; 17th Ed 2008
- Robbins and Cotran Pathologic Basis of Disease"; Vinay Kumar et al.; 8th Ed 2009
