Diabetes mellitus is a chronic disease in which the body produces little or no insulin or resists the insulin that it does produce. Insulin transports glucose into the cells for use as energy and storage as glycogen. It also stimulates protein synthesis and free fatty acid storage in the fat deposits. When a person lacks sufficient insulin, body tissues have less access to essential nutrients for fuel and storage.
The incidence of diabetes mellitus is equal in men and women and rises with age. The disease increases the risk of heart attack, stroke, kidney failure, and peripheral blood vessel disease. What’s more, it’s a major cause of blindness in adults.
There are two main forms of diabetes mellitus: Type I or insulin-dependent, and the more prevalent Type II or non-insulin-dependent. Type I usually occurs before age 30, although it may strike at any age. Type II usually occurs in obese adults over age 40. It’s most often treated with diet and exercise (possibly in combination with drugs that lower the blood sugar level), although treatment sometimes includes insulin therapy.
What Causes it?
The cause of diabetes mellitus remains unknown, but genetic factors may playa part in development of the disease. In Type I diabetes, cells in the pancreas that produce insulin are damaged, possibly because of an immune system problem. Consequently, these cells are able to produce very little or no insulin.
In Type II diabetes, the cells in the pancreas are still able to produce insulin, but not enough to meet the body’s needs. People with this type of diabetes are usually obese.
Other forms of diabetes, called secondary diabetes, may be caused by pregnancy, physical or emotional stress, or the use of certain medications.
What are its Symptoms?
All types of diabetes produce similar symptoms. The most common symptom is fatigue, caused by energy deficiency and abnormal processing of fats, carbohydrates, and proteins. Insulin deficiency causes high blood sugar. High blood sugar, in turn, causes increased and frequent urination, dehydration, excessive thirst, dry mucous membranes, and dry skin. Some people with diabetes may experience weight loss, as fat and muscles are burned up to provide energy and excessive amounts of glucose are excreted in the urine.
Symptoms of Type I diabetes may develop rapidly within weeks or months. Symptoms of Type II diabetes usually develop more gradually and may not appear until many years after the onset of the disease.
If not properly managed, diabetes may also lead to dangerous metabolic crises, such as ketoacidosis and hyperosmolar nonketotic syndrome. These crises result from excessive amounts of glucose in the blood and may lead to fluid loss and shock.
Long-term effects of diabetes may include retinal changes, kidney problems, atherosclerosis (plaque buildup in the arteries), and nervous system problems, such as pain or numbness in hands and feet or paralysis of the stomach resulting in nausea. Other nervous system effects include impotence, nighttime diarrhea, and dizziness when rising to an upright position (due to low blood pressure).
High levels of sugar in the blood encourage bacterial growth and reduce resistance to infection, possibly leading to skin and urinary tract infections and vaginal inflammation.
How is it Diagnosed?
When making a diagnosis of diabetes mellitus, the doctor observes the person for symptoms of uncontrolled diabetes. He or she will order blood tests to measure sugar levels. A blood sugar level equal to or above 200 milligrams per deciliter suggests diabetes mellitus. Another test for diabetes mellitus, called the fasting plasma glucose test, requires fasting for 12 or 14 hours before blood is drawn.
An eye examination may show retinal abnormalities. Other diagnostic and monitoring tests include urinalysis and additional blood tests.
How is it Treated?
The goal of treatment is to normalize the person’s blood sugar level. In Type I, this is achieved with insulin injections, diet, and exercise. The person may receive insulin in a single-dose, mixed-dose, splitÂmixed dose, or multiple-dose regimen. For a multiple-dose regimen, an insulin pump may be used. Insulin may be rapid-acting (regular), intermediate-acting (NPH), long-acting (ultralente), or a combination of rapid-acting and intermediate-acting (Mixtard); it may be standard or purified, and it may be derived from beef pork, or human sources. Today, purified human insulin is commonly used.
A person with either Type I or Type II diabetes must follow a strict diet to meet nutritional needs, control blood sugar levels, and reach and maintain appropriate weight. The person must follow the diet consistently and eat meals at regular times.
For an obese person with Type II diabetes, dietary measures aim to promote weight reduction. In many cases, diet alone may be sufficient to control Type II diabetes. Alternatively, a person with Type II diabetes may take oral antidiabetic drugs to stimulate the body’s insulin production, increase the cells’ sensitivity to insulin, and stop the formation of carbohydrates from noncarbohydrate sources in the liver.
Some people with diabetes may be candidates for pancreas transplantation to help them produce insulin. But this procedure is experimental and requires long-term use of drugs that suppress the immune system.
A diabetic with kidney failure may receive dialysis or a kidney transplant. A person with retinal abnormalities may undergo a procedure called photocoagulation, in which a laser or xenon arc light is used to cause condensation of protein material in the eye. Blood vessel disease may require vascular surgery.
What can a person with diabetes mellitus do?
Be sure to comply with your prescribed treatment program. Make sure you understand – and follow – your doctor’s instructions on managing minor illnesses, such as a cold, flu, or upset stomach. (For instance, you may need to increase your insulin dosage.)
For more information on this disease, contact the Juvenile Diabetes Foundation or the American Diabetes Association.