Diabetes

Diabetes

Diabetes mellitus is a medical disorder characterized by varying or persistent hyperglycemia (elevated blood sugar levels), especially after eating. All types of diabetes mellitus share similar symptoms and complications at advanced stages. Hyperglycemia itself can lead to dehydration and ketoacidosis. Longer-term complications include cardiovascular disease (doubled risk), chronic renal failure (it is the main cause for dialysis), retinal damage which can lead to blindness, nerve damage which can lead to erectile dysfunction (impotence), gangrene with risk of amputation of toes, feet, and even legs. The more serious complications are more common in people who have a difficult time controlling their blood sugars with medications (glycemic control).

The most important forms of diabetes are due to decreased or the complete absence of the production of insulin (type 1 diabetes), or decreased sensitivity of body tissues to insulin (type 2 diabetes, the more common form). The former requires insulin injections for survival; the latter is generally managed with diet, weight reduction and exercise in about 20% of cases, though the majority require these strategies plus oral medication (insulin is used if the tablets are ineffective).

Causes and types

Since insulin is the principal hormone that regulates uptake of glucose into cells (primarily muscle and fat cells) from the blood, deficiency of insulin or its action plays a central role in all forms of diabetes.

Type 1 diabetes

Type 1 diabetes (formerly known as insulin-dependent diabetes, childhood diabetes, or juvenile onset diabetes) is most commonly diagnosed in children and adolescents, but can occur in adults as well. It is characterized by ß-cell destruction, which usually leads to an absolute deficiency of insulin. Most cases of type 1 diabetes are immune-mediated characterized by autoimmune destruction of the body's ß-cells in the Islets of Langerhans of the pancreas, destroying them or damaging...