Diabetes Mellitus

Diabetes Mellitus

Diabetes mellitus is a very common disease affecting more and more people each year, currently affecting about 18.2 million Americans. It is the third leading cause of death in the United States. Diabetes is a disease in which the pancreas inefficiently produces insulin for the body, resulting in too much sugar in the body. After being diagnosed with diabetes, there are lifetime treatments and lifestyle changes. The World Health Organization classifies the three main forms of diabetes as type I, type II and gestational diabetes, which is a special form of diabetes mellitus. These are not single diseases, rather a form or type, describing the patterns of pancreatic failure.

Diabetes mellitus was first seen as a large production of urine. The term diabetes is derived from the Greek term to describe the over abundance of urine. Later mellitus was added to the name to indicate that the urine secreted was sweet. This, along with excessive muscle loss of the first signs of diabetes in the ancient world. Now, much more about diabetes and its causes are known.

In order for the body to have enough energy, the beta cells of the islets of Langerhans of the pancreas produce insulin which then allows glucose (sugar) to enter the body's cells for energy production. Insulin plays a major part in metabolizing carbohydrates, lipids and amino acids. Glucose enters the body through the food that we eat and when insulin is present, it is metabolized and used by the body's cells to produce the essential fuel for the body. When however, the body lacks insulin, or when insulin is not able to bind to its target tissues, it causes hyperglycemia, which means there is a high amount of sugar in the blood, and the glucose entering the body is not being used to produce the energy the body needs. Insulin can be counteracted by glucagons, pituitary growth hormone, steroid hormone and epinephrine. Any interference with insulin and its intended actions leads to hyperglycemia, the most important sign of diabetes mellitus.

The three main reasons which can cause diabetes are an absolute deficiency of insulin, a relative deficiency of insulin and interference with insulin binding to target tissues. This causes the different types of diabetes. Type I diabetes occurs when a person's immune system attacks itself and destroys the beta cells of the pancreas which then interferes with the body's production of insulin. The damage to the beta cells is irreversible. In this type, the body is not able to produce a sufficient amount of insulin and must receive insulin from an outside source to keep the blood sugar level in a normal range. Type I can occur in anybody but more often in children and adolescents and has a lower incidence than type II. In type II diabetes, the most common of all types, beta cells are usually unchanged or sometimes there are even an increased number of beta cells. Type II is usually seen as insulin resistance, meaning the body doesn't respond to the production of insulin normally. At first, the pancreas will try to keep up with this added need of insulin but eventually the pancreas wears out from the over production of the extra insulin. Type III, or gestational diabetes, is one which occurs in women during pregnancy. Because of these pathologic changes and hyperglycemia, it causes complications in the body and many other organs are affected as a consequence.

Regardless of the type of diabetes, this disease develops with the occurrence of many other factors. These are hereditary factors as well as environmental factors. Hereditary factors are more prominent in type II diabetes than in type I diabetes. Studies have shown that if both parents have type II diabetes, there is a chance that nearly all of their children will have diabetes. In type I diabetes however, only 40 to 50 percent of a set of twins will both develop the disease, indicating that while inheritance is important, environmental factors must also be looked at. The disease has been linked to viral infections, too much food or too much stress. Type II diabetes has also been linked to obesity but not all obese persons has diabetes and not all type II diabetic patients are obese.

Diabetes can be diagnosed by demonstrating 3 different types of tests. There is the plasma fasting glucose test, the oral glucose tolerance test and the random plasma glucose test. The plasma fasting glucose test measures your blood glucose level after going 8 hours without eating. This test can detect pre diabetes as well. If after not eating anything for 8 hours and your blood glucose level is still greater than normal, the patient probably has diabetes. The oral glucose tolerance test also measures your blood glucose level after going 8 hours without eating and also after 2 hours after drinking a glucose containing beverage. In a random plasma glucose test, your blood glucose level is tested without regard to when your last meal was. This test is used along with an assessment of any previous signs and symptoms.

The clinical findings of diabetes are hyperglycemia and abnormalities of intermediate metabolism related to insulin deficiency, vascular changes caused by diabetes and increased susceptibility to infection. The three classic signs and symptoms which can usually lead to a diagnosis of diabetes are frequent urination, increased thirst, and an increased appetite. One of the most common symptoms is frequent urination because diabetes can cause polyuria and polydipsia. Since there is an excessive loss of