This Thursday at 10/9c
This content requires javascript and flash player version 8.
Diabetes mellitus is a metabolic disorder with abnormally high blood glucose levels (hyperglycemia) as its most prominent feature. During intestinal digestion, carbohydrates and proteins are broken down into simple sugars and amino acids, respectively. The liver converts all of the sugars and some of the amino acids into glucose, a simple sugar that is used for energy by every cell in the body. Glucose passes from the bloodstream into the cells with the help of insulin, a hormone produced by the pancreas (a pear-shaped organ located just below the stomach). By attaching to receptor sites on the surface membrane of a cell, insulin promotes the movement of glucose-transport proteins from the interior of the cell to its surface, where they bind with glucose and carry it into the cell. In diabetes mellitus, several problems may interfere with this process: pancreatic insulin production may be partially or completely impaired, or body cells may become unable to respond to normal amounts of insulin efficiently.
These underlying problems in fact distinguish the two main types of the diabetes. In type 1 diabetes mellitus, also known as juvenile diabetes, the pancreas produces little or no insulin. Type 1 diabetes develops suddenly and most commonly affects those under age 30; the average age of onset is between 12 and 14. However, type 1 diabetes accounts for only about 5 percent of cases of diabetes mellitus. In the much more common type 2 diabetes mellitus, also known as adult-onset diabetes, insulin production by the pancreas is only moderately reduced, but cells are unable to respond efficiently to insulin—a condition referred to as insulin resistance. The onset of type 2 diabetes is usually gradual and tends to affect people over age 40, particularly those who are overweight. Infrequently, an adult may develop type 1 diabetes.
In both type 1 and type 2 diabetes, the hyperglycemia leads to excretion of glucose in the urine and an accompanying increase in urine production. If inadequate amounts of insulin are administered to patients with type 1 diabetes, unrestrained release of fatty acids from adipose(fat) tissue leads to the overproduction of ketone bodies in the liver. Accumulation of ketone bodies can cause a life-threatening condition known as diabetic ketoacidosis (DKA). DKA may occasionally affect those with type 2 diabetes in periods when the body is highly stressed, forexample, during a severe infection.
People with type 2 diabetes are susceptible to another life-threatening condition known as a hyperosmolar nonketotic state, characterized by extremely high blood sugar levels. This condition usually occurs in elderly persons with some other serious underlying illness. An episode of either DKA or the hyperosmolar state may be the first indication that someone has diabetes.
People with diabetes may also suffer from low blood sugar (hypoglycemia) if too much insulin or oral hypoglycemic agent is given for treatment (see Hypoglycemia for more information).
After 10 to 20 years of diabetes, patients are at risk of developing complications, such as vision disorders, kidney damage, and peripheral nerve degeneration (neuropathy). Strict control of blood glucose can delay or prevent these complications. Loss of sensation in the feet may allow injuries to go unchecked and become infected. In addition, people with diabetes are at increased risk for developing narrowing of the coronary arteries (see Coronary Artery Disease for more information) as well as narrowing of arteries supplying the brain and legs. The combination of foot infections and decreased blood supply can lead to gangrene (tissue death), which may require amputation. Diabetes mellitus (and its complications) is the fourth leading cause of death in the United States.
Treatment of type 1 diabetes requires between one and four daily injections of insulin. (Insulin cannot be taken by mouth, since digestive juices would destroy it.) In addition, diet and exercise must be planned carefully to ensure that blood glucose level are neither too high nor too low. Type 2 diabetes may be controlled with a combination of diet, exercise, and weight loss, although medications (including insulin) are usually necessary. Treatment is largely a process of self-management. Although there is no cure, almost all people with diabetes are able to control their symptoms and lead full, productive lives.
For type 1 diabetes: * Daily injections of insulin are necessary. One to four daily injections are required to control blood glucose levels. Long-acting and rapid-acting insulin preparations are available; a combination of the two kinds is often prescribed. * A strict diet and schedule of meals are necessary to control blood glucose levels. Your doctor may recommend a diet low in fat, salt, and cholesterol, and may advise you to see a nutritionist for dietary planning. * Because both exercise and insulin lower glucose levels, exercise and insulin injections must be timed so that they do not combine to cause a dangerous drop in blood sugar(hypoglycemia). * Strict adherence to the timetable of injections, meals, and exercise is necessary for proper management of the disease.For type 2 diabetes: * A diet low in fat and other calories, in addition to regular exercise, is necessary to control weight. * Oral hypoglycemic drugs, such as tolbutamide, chlor propamide, tolazamide, acetohexamide, glybur ide, glipizide, glimepiride, repaglinide, or meglitonide may be prescribed to increase insulin production by the pancreas, if exercise and diet do not lower glucose levels sufficiently. * Other oral agents can reduce insulin resistance (metformin, pioglitazone, and rosiglitazone) or slow the absorption of sugars from the intestine (acarbose and miglitol). * Insulin injections may be necessary in more severe cases of type 2 diabetes, or if a patient with type 2 diabetes contracts an additional illness.For both types of diabetes: * Blood tests to measure glucose levels should be performed as your doctor recommends, one to four times a day. Your doctor will recommend a blood monitoring device to use at home. * Careful attention must be paid to the risk factors for atherosclerosis because of its increased occurrence with diabetes. Those suffering from diabetes should not smoke, should reduce dietary saturated fat, cholesterol, and salt, and should take any medications prescribed for high blood pressure or high cholesterol levels. * People with diabetes should drink generous amounts of water when stricken with another illness, such as the flu, to replace lost fluid and prevent diabetic coma. When ill, people with type 1 diabetes should test their urine for ketones every four to six hours. * People with diabetes should practice good foot care and check their feet every day. Nerve damage from diabetes mellitus reduces sensation in the feet, and small foot problems may turn into major infections. * Laser photocoagulation to prevent the rupture of tiny blood vessels in the eye may help to prevent or treat diabetic retinopathy. Most patients with diabetes need an eye examination by an ophthalmologist at least once a year to detect the earliest manifestations of retinopathy. * Dialysis, an artificial blood-filtering process, may be necessary to treat kidney failure. In advanced cases a kidney transplant may be advised (see Renal Failure, Chronic, for more information). * Amitriptyline, desipramine, or nortriptyline, medications usually used to treat depression, or the anti-seizure medication gabapentin may be prescribed to relieve the pain in the limbs (see Peripheral Neuropathy for more information). * Excellent control of blood glucose levels delays or prevents late complications affecting the eyes, kidneys, and nerves. * Kidney damage can be slowed by controlling blood pressure and using ACE inhibitors. * The American Diabetes Association can provide information about support groups in your area.
For more Johns Hopkins health information, please visit Johns Hopkins Health Alerts.
For medical appointments at Johns Hopkins, please call 866-386-1617.
All information contained within the Johns Hopkins Symptoms and Remedies website is intended for educational purposes only. Consumers should never disregard medical advice or delay in seeking it because of something they may have read on this website.
Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.