As technology and science progress, news reports inundate the health-conscious consumer with terms and information that require research to understand the content. Glucose is often mentioned at the heart of health concern due to its role in diabetes. With the increasing rate of diabetes in both children and adults, questions abound regarding glucose and its purpose.
Carbohydrates
Another popular term, carbohydrates, must be understood before moving on to glucose. Carbohydrates are one of three energy substrates, or fuels, the others being protein and fat. To convert these substrates into usable energy, the body breaks them down through a series of chemical reactions -- collectively termed "metabolism." Carbohydrates are the human body's main energy source and must be converted into glucose. Protein and fat require conversion into glucose, called gluconeogenesis, prior to being used for energy, but these substrates take longer to convert so are not readily available.
Glucose
A simple sugar molecule, glucose travels through the bloodstream to tissues all over the body. When the body is at rest, glucose is stored in the liver and muscles as a complex molecule called glycogen until needed. When the body increases its energy output, for example while running, the glycogen is converted back to glucose and sent to the tissues in the body for immediate use. Without glucose, the body cannot function.
Glucose Control System
Glucose levels in the blood are controlled by hormones, chemicals released to target specific types of cells. Two of the main hormones involved in controlling glucose levels are insulin and glucagon, which are released by the pancreas. When there is an excessive amount of glucose circulating in the bloodstream, referred to as hyperglycemia, the pancreas releases insulin. When there is not enough glucose in the bloodstream, called hypoglycemia, the pancreas releases glucagon. According to the American Diabetes Association, symptoms of hypoglycemia are dizziness, sweating, hunger, headache and pale skin. Hyperglycemia symptoms include extreme thirst and frequent urination.
Diabetes
Diabetes is a metabolic disease that occurs when blood glucose is consistently high. The hormone insulin is not being produced in sufficient amounts, type 1 diabetes, or not performing its transportation duties properly, type 2 diabetes. Type 1 diabetes is treated with insulin, diet and exercise. Type 2 is generally related to lifestyle habits and treated with glucose-lowering medications, diet, exercise and weight loss. Ninety to 95 percent of all cases of diabetes fall into the category of type 2 and may be prevented with proper nutrition and fitness. Diabetes can develop and progress undetected; therefore, regular visits to your doctor are recommended.
Glucose Testing
Testing glucose levels involves drawing a blood sample for laboratory evaluation. This is often done while fasting at least eight hours prior to testing. This procedure may be repeated often and at random times during the day. Generally speaking, glucose levels under 100 mg/dL are within the normal range, while levels from 100 to 125 mg/dL are considered "prediabetes." Levels exceeding 126 may indicate diabetes.
References
- "Physiology of Sport and Exercise"; Jack H. Wilmore, et al; 2008
- American Diabetes Association: Hyperglycemia
- MedlinePlus: Glucose Test
