Overview: Diabetes Mellitus Type 1

By Jessica DuLong Signs and symptoms • Who gets it • What is happening to the body • Prevention • What you can do at home • When you should see a doctor • Treatment • Additional Resources

Diabetes mellitus type 1 (DM 1) is a disorder of the pancreas that results in the body’s inability to turn food into energy. An auto-immune disease, DM1 results when the immune system turns against the pancreas, leaving it unable to produce insulin. Without insulin, the body cannot get nutrients to the cells of the body’s tissues.

More than 10 million people in the United States have been diagnosed with diabetes. An estimated 5 million others, however, are unaware that they have the disorder. Symptoms of DM 1 include extreme thirst and hunger, unexplained weight loss, and frequent urination. Once these symptoms are identified, and a diagnosis is made, prompt treatment is necessary to restore the body’s ability to feed its own cells. Because insulin is essential to the body’s ability to process energy from food, DM 1 is a serious illness that requires constant maintenance. The primary treatment for DM 1 is lifelong insulin replacement therapy.

Signs and symptoms

Extreme thirst and hunger; unexplained weight loss despite increased appetite; frequent urination of a large volume; blurred vision; fatigue; confusion; nausea and vomiting; frequent infections of the skin, urinary tract or vagina.

What is diabetes mellitus type 1?

Diabetes mellitus type 1 (DM 1) is an autoimmune disease of the pancreas that impairs the body’s ability to metabolize energy from food. It is believed that DM 1 occurs when the disease-fighting system in the body mistakenly fights its own tissues, causing damage to the pancreas. The pancreas is responsible for production of the hormone insulin that helps the body process glucose from food into fuel for the cells. Because in most cases the disease develops by the age of 20, DM 1 is commonly called juvenile-onset diabetes.

Who gets it?

Each year, about 798,000 people are diagnosed with diabetes. According to the National Diabetes Information Clearinghouse, an estimated 16 million people in the United States have diabetes mellitus but about half of them are unaware they have the disease. Diabetes is one of the most common chronic disorders in children in the United States. About 123,000 children and teenagers have diabetes.

Diabetes is widely recognized as one of the leading causes of death and disability in the United States.

DM 1 occurs more commonly in white Americans than among African or Asian Americans, yet is found equally among males and females.

Although the exact mechanism of inheritance is not yet understood, there does appear to be a genetic component to the disease. Inherited characteristics alone are not sufficient to produce the disease without the influence of other environmental factors. However, nearly 2 of every 3 people with the disease come from a family with some history of diabetes.

What is happening in the body

Diabetes mellitus type 1 (DM 1) is a disorder of the pancreas, a long, thin organ located behind the stomach. The pancreas plays a key role in digestion, producing the hormones necessary to process food for use in the body’s cells. Under normal conditions, the concentration of glucose in the blood changes in response to a variety of conditions — meals, exercise, stress, and infection — but remains within a set limit.

Crucial to the body’s ability to process the energy from food into fuel for the cells is insulin, a hormone produced by the pancreas. Under normal conditions, insulin is produced when the concentration of glucose in the bloodstream increases, usually after a meal. Insulin stimulates muscle and fat cells, among others, to absorb glucose in order to fuel their activities. Other pancreatic hormones, such as glucogon and somatostatin, help facilitate the mobilization of the body’s stores of glucose.

When the pancreas has been damaged by DM 1, the delicate balance of regulatory hormones is disrupted. When the immune system attacks the pancreas, damage of the beta cells of the pancreas makes the organ unable to produce sufficient insulin.

Without insulin, the muscle and fat cells are unable to absorb the glucose they need for fuel. Because the cells are unable to absorb the glucose from the blood, levels of the sugar in the blood continue to rise until glucose begins to escape through the kidneys into the urine, carrying with it large amounts of water. This results in an increased volume of urine production, symptomatic of DM 1, which can lead to dehydration.

Because the body is unable to get energy from food, it seeks fuel from fat stores. The breakdown of the body’s stored fat causes rapid and extreme weight loss, another symptom of DM 1.

In response to a lack of energy, the fat pours out of the fat cells so quickly that the body is unable to process the products resulting from its breakdown. The products, called ketone bodies, can cause serious problems for someone with DM 1. Although ketone bodies do not harm most people, in people with DM 1, an excess of acidic ketone bodies can cause diabetic ketoacidosis (DKA) an emergency condition of excess acidity of the blood. As the body attempts to remove the excess of ketone bodies, they are released in the urine and through the breath giving it a fruity smell. DKA is a potentially fatal condition that requires immediate treatment in a hospital.

Because it impairs metabolism, the body’s way of fueling itself, the effects of diabetes on the body are far-reaching. A systemic illness, DM 1 predisposes those with the disease to other medical problems. These include:

At particular risk in people with DM 1 are the following areas of the body:

According to the National Diabetes Information Clearinghouse, diabetes is associated with long-term complications that affect almost every major part of the body. It contributes to blindness, heart disease, strokes, kidney failure, amputations, and nerve damage. Uncontrolled diabetes can complicate pregnancy, and birth defects are more common in babies born to women with diabetes. The following are late complications which can result from diabetes: