ABSTRACT
An average meal usually contains carbohydrates, proteins, and fat. The carbohydrates absorbed from the gastrointestinal tract are then converted to glucose. Much of the absorbed glucose is catabolized by body cells to carbon dioxide and water to provide the body with essential energy. The blood glucose level (BGL) in healthy humans is usually maintained within the normal range of 4-8 mM or 70-120 mg/dL [1]. This level is elevated following a meal, but in healthy subjects it should return to the normal range within 3 h. If the BGL remains elevated above the normal level after the 3 h period or during fasting, this is referred to as hyperglycemia. In cases of hyperglycemia, the BGL may reach as high as 300-700 mg/100 ml. On the other hand, if the BGL drops below the normal level, a state referred to as hypoglycemia, the subject or patient may experience fainting, coma, or even death. The BGL in a hypoglycemic patient can fall as low as 30 mg/100 ml. If hyperglycemia or hypoglycemia conditions persist due to impaired physiological function, then the subject is diagnosed as having diabetes mellitus. Nondiabetic pregnant women or patients suffering from certain medical stresses may also temporarily exhibit symptoms of diabetes caused by irregular hormone levels in the blood.
