DOCTOR'S VIEW ARCHIVE

Diabetes Mellitus - The Work Pays Off

Diabetes mellitus, commonly referred to as diabetes, means sweet urine. It is a chronic medical condition associated with abnormally high levels of sugar (glucose) in the blood. Elevated levels of blood glucose (hyperglycemia) lead to spillage of glucose into the urine, hence the term sweet urine.

Normally, blood glucose levels are tightly controlled by insulin, a hormone produced by the pancreas. Insulin lowers the blood glucose level. When the blood glucose elevates (for example, after eating food), insulin is released from the pancreas to normalize the glucose level. In patients with diabetes mellitus, the absence or insufficient production of insulin causes hyperglycemia.

Diabetes mellitus is a chronic medical condition, meaning it can last a life time. Over time, diabetes mellitus can lead to blindness, kidney failure, and nerve damage. Diabetes mellitus is also an important factor in accelerating the hardening and narrowing of the arteries (atherosclerosis), leading to strokes, coronary heart diseases, and other blood vessel diseases in the body.

Diabetes mellitus affects 12 million people (6% of the population) in the United States. The direct and indirect cost of diabetes mellitus is $40 billion per year. It is the third leading cause of death in the United States after heart disease and cancer.

In the United States, diabetes mellitus is the leading cause of new blindness in adults, kidney failure, and amputations (not caused by injury). The lack of insulin, insufficient production of insulin, production of defective insulin, or the inability of cells to use insulin leads to elevated blood glucose (sugar) levels, referred to as hyperglycemia, and diabetes mellitus.

Glucose is a simple sugar found in food. Glucose is an essential nutrient that provides energy for the proper functioning of the body cells. After meals, food is digested in the stomach and the intestines. The glucose in digested food is absorbed by the intestinal cells into the bloodstream, and is carried by blood to all the cells in the body. However, glucose cannot enter the cells alone. It needs assistance from insulin to penetrate the cell walls.

Without insulin, cells become starved of glucose energy despite the presence of abundant glucose in the blood. In diabetes mellitus, the cells' inability to utilize glucose gives rise to the ironic situation of starvation in the midst of plenty. The abundant, unused glucose is wastefully excreted in the urine. Insulin is a hormone which is produced by specialized cells (islet cells) of the pancreas. In addition to helping glucose enter the cells, insulin is also important in tightly regulating the level of glucose in the blood.

The pancreas is a deeply seated organ in the abdomen located behind the stomach. After a meal, the blood glucose level rises. In response to the increased glucose level, the pancreas normally releases insulin into the bloodstream to help glucose enter the cells and lower blood glucose levels. When the blood glucose levels are lowered, the insulin release from the pancreas is turned off. In normal individuals, such a regulatory system helps to keep blood glucose levels in a tightly controlled range.

In patients with diabetes mellitus, the insulin is either missing (as in type I diabetes mellitus), or insulin regulation is defective and insufficient (as in type II diabetes mellitus). Both cause elevated levels of blood glucose (hyperglycemia).

The long-term complications of diabetes mellitus result from the effect of hyperglycemia on the blood vessels. Blood vessel damage eventually leads to disease of the eyes (retinopathy), nerves (neuropathy), and kidneys (nephropathy) For patients with type I diabetes mellitus, tight control of the blood sugar was ultimately proven in 1993 to decrease the frequency and intensity of the effects of diabetes on the eyes, nerves, and kidneys.

For patients with type II diabetes mellitus, proof of the benefit (in terms of reduction of long-term complications) of careful control of blood sugar has awaited further research studies. A study published in Annals of Internal Medicine (1997;127:788-795) documents substantial benefit from careful control of the blood sugar in patients with type II diabetes mellitus.

Sandeep Vijan, M.D. and colleagues at the University of Michigan found that patients with type II diabetes mellitus who diligently kept their blood sugar levels as close as possible to normal over time had far less kidney and eye disease than those who did not. This effect was especially significant for patients whose diabetes was detected at younger ages (less than 50 years of age).

This important study suggests that good control of the blood sugar over time is extremely important for patients with type II diabetes mellitus as well as type I. Therefore, while meticulous sugar control in patients with diabetes mellitus can take substantial effort from both patient and doctor, in the long run it pays off.

For more information visit the MedicineNet.com Diabetes Mellitus Center.


Last Editorial Review: 7/8/2002