Your body’s favorite fuel is a simple sugar called glucose. When you digest sugary or starchy foods, lots of glucose enters your bloodstream. Yet in a healthy person, the blood glucose level stays remarkably stable, regardless of what that person eats. The pancreas and the liver work together to keep the blood sugar within a narrow range. The pancreas releases two different hormones that help to control blood sugar.
When blood sugar levels are high, the pancreas produces insulin. Insulin is the hormone that helps you cope with a meal. Insulin tells your liver and muscles to store some of the incoming glucose as a starch called glycogen. It also allows your heart and muscles to use plenty of glucose for fuel. Insulin tells your fat cells to store fat. Insulin also encourages cells all over the body to use amino acids to make proteins.
When blood sugar levels are low, the pancreas releases less insulin. When insulin levels are low, the alpha cells of the pancreas start to release another hormone, called glucagon. Glucagon is the hormone that allows your body to survive a fast. Glucagon tells your liver to make fresh glucose out of glycogen and out of other things, such as some amino acids. Glucagon also tells your fat cells to release stored fat, to feed the rest of the body. Glucagon even tells other cells to break down proteins so that the amino acids can be converted to sugar.
Now that you know what insulin and glucagon do, you can see how dangerous thin diabetes is. If you have no insulin, your liver will have no way to know that you have enough sugar in your blood. Because of the shortage of insulin, the pancreas will produce glucagon, even if your blood sugar is already high. If you have lots of glucagon but no insulin in the blood, your liver will react as if you are about to die of low blood sugar. It will make glucose as fast as it can, out of anything it can. When the blood glucose rises to abnormally high levels, some of that glucose will leak out through the kidneys, taking water with it.When the liver is making sugar as fast as it can, it will use up one of the substances that it needs for burning fat in the normal way. As a result, some of the fat will be broken down into keto acids. Ketosis means that there is an abnormally large amount of keto acids in the bloodstream. These processes causes the classic signs of diabetes:
- Abnormally large volume of urine (polyuria)
- Dehydration and thirst (polydipsia)
- Sugar in the urine (glycosuria)
- Weight loss
- Fruity smell of the breath (from ketosis)
If thin diabetes goes untreated, the person will eventually end up in a state called diabetic ketoacidosis. This condition is a medical emergency that consists of the following four problems:
- High blood sugar
- Acidosis (low blood pH)
- Electrolyte imbalance
Before the discovery of insulin, a starvation diet was the only available treatment for thin diabetes. The goal was to allow the patient to starve to death slowly, rather than going into a coma and dying within a matter of days or weeks. Even today, thin diabetes is a serious problem. In a healthy person, the pancreas and liver work together to keep the blood sugar in the normal range. A person with thin diabetes has to take over this responsibility.