Diabetes mellitus

Alternative names:

diabetes; sugar diabetes

Definition:

A disorder caused by decreased production of insulin, or by decreased ability to use insulin. Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar.

Causes, incidence, and risk factors:

The cause of diabetes mellitus is unknown, but heredity and diet are believed to play a role in its development. Diabetes results when the pancreas produces insufficient amounts of insulin to meet the body's needs. It can also result when the pancreas produces insulin, but the cells are unable to efficiently use it (insulin resistance). Insulin is necessary for blood sugar (glucose) to go from the blood to the inside of the cells, and unless the sugar gets into the cells, the body cannot use it. The excess sugar remains in the blood and is then removed by the kidneys. Symptoms of excessive thirst, frequent urination, and hunger develop. The (metabolism) of carbohydrates, fats, and proteins is altered.

Diabetes occurs in several forms. The most common types are: Type I, or insulin-dependent diabetes mellitus (IDDM); Type II, or noninsulin-dependent diabetes mellitus (NIDDM); and Gestational Diabetes Mellitus.

Insulin-dependent diabetes mellitus (IDDM or Type I) usually occurs in people before the age of 30, who must then receive insulin injections. Risk factors for IDDM include autoimmune disease, viral infections, and a family history of diabetes.

Noninsulin-dependent diabetes mellitus (NIDDM or Type II) usually occurs in severely overweight(obese) adults and rarely requires insulin treatment. Treatment includes diet for diabetics and exercise. Risk factors for Type II are obesity, physiological or emotional stress, pregnancy, certain medications, age over 40, and family history.

Gestational diabetes starts or is first recognized during pregnancy. It usually becomes apparent during the 24th to 28th weeks of pregnancy. In many cases, the blood glucose level returns to normal after delivery. Risk factors for gestational diabetes are maternal age over 25 years, family history of diabetes, obesity, birth weight over 9 pounds in a previous infant, unexplained death in a previous infant or newborn, congenital malformation in a previous child, and recurrent infections.

Diabetes mellitus affects up to 5% of the population in the US, almost 14 million people.