Most people have witnessed, at some point a friend or a family member inject themselves with a needle after a meal. What causes them to do this? Diabetes! They are injecting themselves with insulin, a hormone that is in short supply in diabetics. Insulin is produced by the pancreas, a small gland near the stomach. Its primary function is to control the levels of sugar in the blood by facilitating the entry of glucose into body cells. Cells need glucose, a sugar that serves as a prime energy source. If cells in our bodies lack insulin they will not have access to glucose. As a result they will lack the energy needed to fuel the myriad reactions the cell has to carry out. These reactions are important for the proper functioning of our heart, liver and eyes and an insulin deficiency therefore can cause heart disease, liver problems and blindness.
Insulin is found in the body at all times with levels normally elevated after meals. Food contains carbohydrates which are metabolized in the body to glucose. As glucose levels in the blood rise, the pancreas begins to secrete insulin, the "gatekeeper" for glucose. If there is not enough insulin to marshall glucose into cells, a condition known as hyperglycemia results. The symptoms are extreme tiredness, drowsiness, dry mouth, thirst and a frequent urge to urinate. The word diabetes actually derives from the Greek expression "running through."
Hyperglycemia, or high blood sugar, comes about when the body makes very little or no insulin. In cases of type 1 diabetes, also known as insulin-dependent diabetes, the pancreatic cells are completely destroyed and no longer produce insulin. Therefore treatment consists of direct injections of insulin. This must be done carefully because too much insulin can cause glucose levels to plummet, resulting in a condition known as hypoglycemia. The symptoms of hypoglycemia include shakiness, cold sweats, hunger, headaches, nervousness, numb or tingling lips and tongue. Type 1 diabetes is mostly hereditary and generally shows up before the age of 20.
In cases of type 2 diabetes, the pancreas produces some insulin but it is not enough. Furthermore, the insulin produced does not work the way it should. The majority of all diabetic cases (about 85%) are of the type 2 variety. Often, obesity plays a key role in causing "insulin resistance" even if a person is not diabetic. Therefore, weight reduction is an important factor in improving responsiveness to insulin. Endurance type exercise is an excellent way to control type 2 diabetes. Insulin injections are usually not necessary but drugs such as GlucoNorm are administered to help release insulin when a patient needs it most, namely after mealtime.
People affected by insulin imbalances (diabetics) must test their blood sugar levels on a daily basis. These tests are the only way to know if the insulin supplements or dietary controls are working properly. Blood sugar can be tested before eating, and the amount and variety of food to be consumed can be planned accordingly.
Before 1921 A.D., millions of people died every year due to the body's inability to process glucose properly. But the world of diabetics changed for ever when Frederick Banting, a Canadian physician, visited the University of Toronto to speak to the head of the department of physiology, John J.R. Macleod. Macleod had studied glucose metabolism and diabetes and Banting had a new idea about finding the cause of and a treatment for the so- called "sugar disease." Macleod gave him a lab and an assistant, Charles Best. The duo began by surgically removing the pancreas from dogs and quickly discovered the cause of the disease-lack of insulin. The obvious course of action was to try and inject insulin into a diabetic. That is just what they did on February 13, 1922! Their 14 year-old patient showed almost instant improvement. In 1923, the Nobel Prize was awarded to Banting and Macleod for the discovery of insulin, with each one sharing their portion of the prize money with the other researchers on the project.
The insulin used was mostly derived from pigs and cows because of their great similarity to human insulin. However, sometimes the slight difference in the structure of animal insulin was enough to trigger an allergic reaction. Today, this problem has been minimized because human insulin can be produced by genetic engineering techniques. Still, insulin treatment is a complicated business. There are different varieties of insulin. Some act quickly, others have a more protracted action. Even the site of injection or the activity of a limb can affect the blood levels of insulin. For example, injection into the buttocks results in slower absorption than injection into the abdomen. Also, the colder the temperature, the slower the absorption rate. Depending on a person's diet and daily activities, there are ways to combine the use of different insulins to create a suitable plan for each individual. It is also important to alternate injection sites within the same region to maintain consistency and absorption of the insulin. The abdomen is the preferred region since it is less affected by exercise. It is important to note that insulin cannot be given orally because the acids in the stomach would destroy the hormone before it begins to work. Moreover, injections have become relatively painless because insulin is dispensed in syringes that are very thin and short.
Today only two companies in the world manufacture insulin, Lily Inc and Nordisk. But in the future diabetics may have a whole new life style. Some companies are working on oral insulin puffs while others are using NASA technology to surgically implant a pumping mechanism in a diabetic's abdomen that would enable insulin to be released continuously. Still others are working on transplantations of pancreatic cells into the diseased tissues of diabetics. Hope of a normal life for diabetics is better today than it has ever been.