Q. I have had two episodes of hypoglycemia during which I lost consciousness, but eventually regained it with no intervention from anyone else. How is this possible? Can the body raise its blood glucose level on its own?
A. The body does have a mechanism for raising its blood glucose level, but it cannot be relied on to reverse all cases of hypoglycemia. For that reason, people who use insulin or blood-glucose-lowering pills that can cause hypoglycemia should know how to prevent, detect, and treat hypoglycemia. Those who have lost the ability to sense the early signs of hypoglycemia should talk to their doctors about ways to reverse such hypoglycemia unawareness.
Normally, the body maintains its blood glucose level in a relatively constant range through the actions of insulin (which lowers blood glucose level) and its counter-regulatory hormones (which raise it). When a person's blood glucose level increases, say after eating a meal, the body releases insulin, which causes fat cells and muscle cells to absorb glucose from the blood. When the blood glucose level drops, counter-regulatory hormones such as glucagon and epinephrine cause the liver to release glucose to the blood. However, the pancreatic alpha cells, which produce most of the body's glucagon, are often damaged or deficient in people with type 1 diabetes. People with type 1 diabetes are also prone to losing their epinephrine response to low blood glucose.
Hypoglycemia occurs when there is a relative excess of insulin circulating in the bloodstream. Skipping meals or exercising more than usual can lead to hypoglycemia if corresponding adjustments in diabetes medicines or snacks are not made. In addition, people who take pre-meal short-acting insulin should learn to adjust the insulin dose according to the amount of carbohydrate they're planning to eat to avoid injecting too much and ending up with hypoglycemia.
Symptoms of hypoglycemia vary according to the individual and the size and rate of fall of the blood glucose level. Glucose is the main fuel the brain uses for energy, so low blood sugar levels can lead to irritability, confusion, seizures, and eventually to unconsciousness or coma.
The recommended treatment for hypoglycemia is to eat something containing 15 grams of carbohydrate. People who take insulin or sulfonylureas such as Glucotrol, Amaryl, and DiaBeta should always carry a source of glucose with them. Many people use glucose tablets for this purpose. If hypoglycemic symptoms make a person unable to swallow, glucose gel can be applied to the gums. A person with type 1 diabetes and their family members should also have an emergency glucagon injection kit.
Because the body can release hormones that stimulate the liver to release glucose, it is possible your blood sugar may rise enough to help you recover from hypoglycemia even if food is not eaten. However, because of the progressive unreliability of the body's innate response to low blood glucose in people with diabetes, a person who experiences frequent episodes of hypoglycemia, especially those severe enough to require the assistance of others, should speak with his diabetes team about making changes in his treatment regimen.
By Robin Goland, MD, Co-director, Naomi Berrie Diabetes Center, Columbia Presbyterian Medical Center, and Irving Associate Professor of Medicine, Columbia University College of Physicians & Surgeons, New York, New York.
Reprinted with permission from Diabetes Self-Management. Copyright � 2003 R.A. Rapaport Publishing, Inc. For subscription information, call (800) 234-0923.