Diabetes Mellitus Health Article
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Definition
Diabetes mellitus is a condition that occurs when either the pancreas does not produce enough insulin or the body's cells stop responding to the insulin that is produced. In either case, glucose in the blood cannot be absorbed or used by the cells of the body.
Description
Diabetes has been recognized as a disease since ancient times. Egyptian papyri described its symptoms in 1550 B.C., and Hindu physicians noted 500 years later that insects were drawn to the sugary urine of people afflicted with diabetes. The disease was first named in 230 B.C. by Apollonius of Memphis, who took it from the Greek diabainein (to pass through), a description of the unquenchable thirst and copious urine produced by diabetics. It was not until the latter part of the eighteenth century that the British physician John Rollo appended the Latin term mellitus (honey-sweet) to distinguish diabetes from other diseases that caused excessive urine production.
Diabetes mellitus is a chronic disease that causes serious health complications including renal failure, heart disease, stroke, blindness, and peripheral neuropathy with vascular insufficiency, putting patients at risk for gangrene and subsequent amputation of the extremities. Approximately 16 million Americans have diabetes; of these, it is estimated that around 5.4 million are undiagnosed. Diabetes afflicts 120 million people worldwide, with the World Health Organization predicting that the number will reach 300 million by 2025.
Physiology
Every cell in the human body requires fuel to function. The body's primary energy source is glucose, a simple sugar resulting from the digestion of foods containing carbohydrates. Glucose from the digested food circulates in the blood as a ready energy source for any cells that need it. Insulin is a protein hormone secreted into the blood by cells in the pancreas called islets of Langerhans. Insulin bonds to a receptor site on the outside of a cell, and acts like a key to open a doorway into the cell through which glucose can enter. The liver may convert excess glucose to concentrated energy sources like glycogen or fatty acids, which are stored for later use. If there is insufficient insulin production, or when the doorway no longer recognizes the insulin key, glucose stays in the blood rather than entering the cells.
As the level of glucose in the blood rises, a condition called hyperglycemia results. The body will try to dilute this high blood glucose level by drawing water out of the cells, pumping it into the bloodstream, and excreting it in urine. It is not unusual for those with undiagnosed diabetes to complain of constant thirst, to drink large quantities of fluids, and to urinate frequently as their bodies attempt to get rid of the extra glucose.
At the same time that the body is attempting to rid itself of glucose in the blood, its cells are starving for glucose and sends signals to eat more food, giving patients tremendous appetites. To provide energy for the starving cells, the body also tries to convert fats and proteins into glucose. Breaking down these substances causes acid compounds called ketones to form in the blood and to be excreted in the urine. As ketones build up in the blood, a condition called ketoacidosis can occur. If left untreated, this condition can be life threatening, eventually leading to coma and death.
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Author Info: Deanna M. Swartout-Corbeil, R.N., The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Nursing and Allied Health, 2002 |
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