Insulin-dependent diabetes mellitus (IDDM)

Alternative names:

diabetes mellitus - type I; IDDM; juvenile onset diabetes; type I diabetes mellitus

Definition:

A chronic disease of the pancreas that results when too little insulin (a hormone released in response to increased levels of sugar in the blood) is released into the body.

Causes, incidence, and risk factors:

Diabetes mellitus is a life-long disease for which there is not yet a cure. There are several forms of diabetes mellitus: insulin-dependent diabetes mellitus (IDDM or Type I); noninsulin-dependent diabetes mellitus (NIDDM or Type II); and gestational diabetes mellitus. The metabolism of carbohydrates, proteins, and fats are altered.

In insulin-dependent diabetes mellitus, the beta cells of the pancreas produce little or no insulin, a hormone that allows glucose to enter body cells. With inadequate insulin, glucose or sugar builds up in the bloodstream instead of going into the cells. The body is unable to use glucose for energy despite the high levels of glucose in the bloodstream. This causes the symptoms of excessive thirst, urination, and hunger. Within 5 to 10 years after diagnosis, the insulin producing cells of the pancreas are completely destroyed, and there is absolute insulin deficiency.

IDDM can occur at any age, but usually occurs before 30 years old in people who are usually lean. Symptoms are usually more severe with this type of diabetes, and the symptoms develop rapidly. People with this condition require insulin to live. The exact cause of Type I diabetes is not known; however, a family history of diabetes, viruses that have injured the pancreas, and destruction of insulin-making cells by the body's immune system may play a causative role. Risk factors for Type I include autoimmune disease, viral infections, and a family history of diabetes.

Insulin-dependent diabetes accounts for 3% of all new cases of diabetes each year. There is 1 new case per 7,000 children per year, and the incidence decreases after 20 years old.