Diabetes Mellitus

There are three major types of diabetes: type 1, type 2, and gestational diabetes. Type 1 diabetes was previously called insulin-dependent diabetes or juvenile-onset diabetes. Type 1 diabetes develops when the body's immune system destroys pancreatic beta cells, the only cells that produce insulin. The body, in turn, produces little or no insulin, resulting in insulin deficiency. Without insulin, the body is unable to use glucose for energy and begins to break down fats for fuel. Ketones are formed when fat is burned for energy. Excess ketones build up in the blood and lower the blood pH value leading to ketoacidosis.

Symptoms of type 1 diabetes usually appear suddenly and include increased thirst, frequent urination, increased hunger, tiredness, and weight loss. Risk factors for type 1 diabetes include autoimmune, genetic, and environmental factors. Although it usually begins when people are under the age of 30, type 1 diabetes may occur at any age. Almost 10% of the United States diabetes population has type 1 diabetes.

Type 2 diabetes was previously called noninsulin-dependent or adult onset diabetes. It begins as insulin resistance, a disorder in which normal to excessive amounts of insulin is made by the body, but the cells cannot use insulin properly. The ability to make insulin gradually decreases with time due to the progressive nature of the disease. In its early stages, type 2 diabetes often has no symptoms. When they do occur, symptoms may initiate gradually and include fatigue, dry skin, numbness or tingling in hands or feet, frequent infections, slow healing of cuts and sores, problems with sexual function, and increased hunger and thirst. With type 2 diabetes, hyperosmolar coma can develop from blood glucose levels (often referred to as blood sugar) becoming dangerously high. If the elevated blood sugar is not adequately controlled, it can cause severe dehydration, a serious condition requiring immediate treatment. Type 2 diabetes is associated with obesity, family history of diabetes, prior history of gestational diabetes, impaired glucose tolerance, physical inactivity, and race/ethnicity. Type 2 diabetes is diagnosed in children and adolescents in increasing numbers. About 85% of the U.S. diabetes population has type 2 diabetes.

Gestational diabetes occurs during pregnancy and affects 4% of all pregnant women. During pregnancy, the placenta supplies the baby with glucose and water from the mother's blood. Hormones made by the placenta are needed for pregnancy, but can keep the mother's insulin from functioning effieciently. As the pregnancy continues, more of these hormones are manufactured. When the mother is not able to make enough insulin to compensate for the increased hormone levels and to maintain normal blood glucose, gestational diabetes develops. Treatment is required to normalize maternal blood glucose levels to avoid complications in the fetus. After pregnancy, up to 10% of women with gestational diabetes are found to have type 2 diabetes. Women who have had gestational diabetes have a 20%–50% chance of developing diabetes in the next 5–10 years.