Type 1 diabetes

DEFINITION

Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition in which the pancreas produces little or no insulin, a hormone needed to allow sugar (glucose) to enter cells to produce energy. The far more common type 2 diabetes occurs when the body becomes resistant to insulin or doesn’t make enough insulin.

Various factors may contribute to type 1 diabetes, including genetics and exposure to certain viruses. Although type 1 diabetes usually appears during childhood or adolescence, it also can begin in adults.

Despite active research, type 1 diabetes has no cure. But it can be managed. With proper treatment, people with type 1 diabetes can expect to live longer, healthier lives than did people with type 1 diabetes in the past.

CAUSES

The exact cause of type 1 diabetes is unknown. In most people with type 1 diabetes, the body’s own immune system — which normally fights harmful bacteria and viruses — mistakenly destroys the insulin-producing (islet) cells in the pancreas. Genetics may play a role in this process, and exposure to certain environmental factors, such as viruses, may trigger the disease.

The role of insulin

Once a significant number of islet cells are destroyed, you’ll produce little or no insulin. Insulin is a hormone that comes from the pancreas, a gland situated behind and below the stomach.

• The pancreas secretes insulin into the bloodstream.
• Insulin circulates, enabling sugar to enter your cells.
• Insulin lowers the amount of sugar in your bloodstream.
• As your blood sugar level drops, so does the secretion of insulin from your pancreas.

The role of glucose

Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues.

• Glucose comes from two major sources: food and your liver.
• Sugar is absorbed into the bloodstream, where it enters cells with the help of insulin.
• Your liver stores glucose as glycogen.
• When your glucose levels are low, such as when you haven’t eaten in a while, the liver converts stored glycogen into glucose to keep your glucose level within a normal range.

In type 1 diabetes, there’s no insulin to let glucose into the cells, so sugar builds up in your bloodstream, where it can cause life-threatening complications.

The cause of type 1 diabetes is different from the cause of the more familiar type 2 diabetes. In type 2 diabetes, the islet cells are still functioning, but the body becomes resistant to insulin or the pancreas doesn’t produce enough insulin or both.

SYMPTOMS

Type 1 diabetes signs and symptoms can come on quickly and may include:

• Increased thirst
• Frequent urination
• Bedwetting in children who previously didn’t wet the bed during the night
• Extreme hunger
• Unintended weight loss
• Irritability and other mood changes
• Fatigue and weakness
• Blurred vision
• In females, a vaginal yeast infection

When to see a doctor

Consult your doctor if you notice any of the above signs and symptoms in you or your child.