Diabetes

Definition

Diabetes mellitus describes a group of diseases in which there is an elevated level of the sugar glucose, the body's main source of energy for cellular functions, in the blood. The level of glucose, as well as other "fuel" molecules, is increased due to a disorder in the production or function of the hormone insulin. A range of health problems occurs primarily due to the damaging effects of elevated levels of glucose on blood vessels.

Description

To understand diabetes, it is important to understand how the hormone insulin functions in the breakdown and utilization of glucose. Insulin acts in two ways. It is necessary for the transport of glucose and other fuel molecules into the cells. It also regulates several pathways in metabolism that are important in the utilization of these fuel molecules. Insulin is made and released by specialized cells of the organ known as the pancreas. These beta cells of the pancreas release insulin when blood levels of glucose, amino acids, fatty acids, and ketones are high. These are all breakdown products of food, and an increase in their level in the blood signals that a person has recently eaten. The insulin acts to mobilize each of these fuel molecules so they can be used as energy to support cellular functions needed to maintain the body.

There are two main types of diabetes mellitus: type I and type II diabetes. While there are similarities, type I and type II diabetes differ in several aspects related to cause, symptoms, treatment, and associated risk factors. In addition, there are other less common forms of diabetes.

Type I diabetes

Also called insulin-dependent diabetes mellitus (IDDM), this is the most severe form of diabetes, in which shots of insulin are necessary on a daily basis. IDDM is thought to be an autoimmune condition in which one's own immune system attacks and destroys the insulin-producing cells of the pancreas. Insulin production is low or absent, and onset is generally in childhood or early adulthood. Affected individuals tend to be thin and prone to events in which ketones can become so high in the blood as to be potentially life-threatening, a complication called ketosis.

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Author Info: Jennifer Denise Bojanowski MS, CGC, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Genetic Disorders Part I, 2002

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.