Diabetes mellitus is a syndrome characterized by relative or absolute deficiency of the hormone, Insulin, with malfunctions in the body's utilization of glucose. There are persistently high levels of glucose, even in the fasting state, with overflow of glucose into the urine.
Nearly 24 million people in the U.S. are estimated to be living with diabetes. The costs of diabetes in terms of treatments and complications stand at over $98 billion a year in direct and indirect costs. The concern is in the predisposition of diabetics to heart disease, atherosclerosis and kidney disease.
Normal Function of the Pancreas
Insulin is produced in a subset of cells of the pancreas, called beta cells, in the Islets of Langerhans. Typically, the pancreas releases adequate amounts of insulin in response to increased blood glucose levels. The released Insulin acts on cells to encourage the uptake of Insulin, leading to a drop in blood levels of glucose. Lowered levels of blood sugar exert a negative feedback effect on the pancreas to shut down insulin release.
The Pancreas in Diabetes
In some people (about 10 percent of diabetics), the pancreas produces insufficient amounts of Insulin, leading to persistently high levels of glucose in the blood, enough to overwhelm the kidneys and overflow into the urine. In these cases, there is usually previous damage to the pancreas, particularly to the islets of Langerhans. Misdirected immune responses have been cited in many cases. In some other cases, infections like mumps, congenital rubella and cytomegalovirus are implicated. Sometimes, primary disease of the pancreas as seen in pancreatitis, pancreatic cancer and cystic fibrosis also destroys the islet cells.The body's response to this deficiency in Insulin leads to a lot of complications. Fat is broken down in an attempt to provide the much needed energy, with the production of ketones as byproducts and the development of the dreaded diabetic ketoacidosis. These conditions require exogenous insulin to overcome the diabetic state. This situation is called insulin dependent diabetes mellitus
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In some patients, the body's response to adequate amounts of secreted insulin is faulty. The pancreas responds to the increased glucose levels by secreting Insulin, but the cells do not respond to insulin as they should. This accounts for most cases of diabetes and is associated with factors like obesity, inactivity, family history and certain ethnic groups. Some drugs like steroids, thyroid hormones and phenytoin work against Insulin or directly suppress the pancreas. At first, the pancreas responds to this demand with increased Insulin secretion, then apparently fails and begins to produce reduced amounts of Insulin. Some medications that stimulate the pancreas to secrete Insulin help in this type of diabetes. Other medications that reduce tissue resistance to Insulin are also used.
Treatment
Under normal circumstances, the pancreas is the sole producer of Insulin in the body. Any perceived deficiency in insulin calls the normal function of the pancreas into question. Treatment of diabetes revolves around making up for the deficiency by stimulating the pancreas to produce more insulin, providing exogenous insulin to make up for the deficiency or reducing tissue resistance to produced or administered insulin.
