Causes of Diabetes

Causes of Diabetes

Diabetes mellitus occurs when the pancreas doesn't make enough or any of the hormone insulin, or when the insulin produced doesn't work effectively. In diabetes, this causes the level of glucose in the blood to be too high.

In Type 1 diabetes the cells in the pancreas that make insulin are destroyed, causing a severe lack of insulin. This is thought to be the result of the body attacking and destroying its own cells in the pancreas - known as an autoimmune reaction.

It's not clear why this happens, but a number of explanations and possible triggers of this reaction have been proposed. These include:

• infection with a specific virus or bacteria;
• exposure to food-borne chemical toxins; and
• exposure as a very young infant to cow's milk, where an as yet unidentified component of this triggers the autoimmune reaction in the body.

However, these are only hypotheses and are by no means proven causes.

Type 2 diabetes is believed to develop when:

• the receptors on cells in the body that normally respond to the action of insulin fail to be stimulated by it - this is known as insulin resistance. In response to this more insulin may be produced, and this over-production exhausts the insulin-manufacturing cells in the pancreas;
• there is simply insufficient insulin available; and
• the insulin that is available may be abnormal and therefore doesn't work properly.

The following risk factors increase the chances of someone developing Type 2 diabetes:

• Increasing age;
• obesity; and
• physical inactivity.

Rarer causes of diabetes include:

• Certain medicines;
• pregnancy (gestational diabetes); and
• any illness or disease that damages the pancreas and affects its ability to produce insulin e.g. pancreatitis.

What doesn't cause diabetes

It's important to also be aware of the different myths that over the years have arisen about the causes of diabetes.

Eating sweets or the wrong kind of food does not cause diabetes. However, it may cause obesity and this is associated with people developing Type 2 diabetes.

Stress does not cause diabetes, although it may be a trigger for the body turning on itself as in the case of Type 1 diabetes. It does, however, make the symptoms worse for those who already have diabetes.

Diabetes is not contagious. Someone with diabetes cannot pass it on to anyone else.

(by Dr. Rob Hicks)

Causes of Diabetes

Drugs such as steroids, Dilantin, and others may elevate the blood sugar through a variety of mechanisms. Certain other drugs, such as alloxan, streptozocin, and thiazide diuretics, are toxic to the beta cells of the pancreas and can cause diabetes. Certain syndromes (for example, Prader-Willi, Down's, Progeria, and Turner's) may result in a hyperglycemic state; if this state is prolonged, the result can be permanent diabetes.

Diabetes resulting in an insulin-dependent state is classified as Type 1 diabetes. While Type 1 diabetes affects only between 5 to10 percent of the diabetic population, its effects on the body can be worse than other forms of diabetes. In the past, Type 1 has been known as juvenile or juvenile-onset diabetes (because it is usually diagnosed in those under thirty), brittle diabetes, unstable diabetes, and ketosis-prone diabetes. People in this classification more frequently exhibit the classic symptoms, usually with ketones present in blood and urine. A blood-sugar level of 800 mg/dl (44 mmol) or more, especially if ketones are not present, indicates a diagnosis of hyperglycemic hyperosmolar nonketotic syndrome (a state in which the body is extremely dry (dehydrated), the chemicals in the body are concentrated, and the blood sugar is high).

As stated before, diabetes is a syndrome or group of diseases (rather than one disease), leading to the prolonged hyperglycemic state. Type 1 is most associated with the killing of the beta cells, most likely by the body's own immune system. Either the immune system cannot kill an infecting agent, which then kills the beta cells, or the immune system itself goes "wild," attacking the body's own tissue and destroying the beta cells. The cells of the islets of Langerhans are inflamed, resulting from an infectious-disease process (for example, mumps) or, more commonly, from an autoimmune (allergic to self) response.

The autoimmune process results in the circulation of antibodies that may either cause or be caused by beta-cell death. If it is found that the antibodies cause beta-cell destruction (the body fighting what it now considers foreign to itself), the body's response to the Type 1 diabetes is much less severe (i.e., easier to control) with treatment. Until then, the outcome is a lack of available insulin. While the onset is said to be sudden, changes resulting in decreased insulin availability may have occurred over a longer period of time. In short, insulin-dependent diabetes mellitus is an inherited defect of the body's immune system, resulting in destruction of the insulin-producing beta cells of the pancreas.

Heredity is a major cause of diabetes. If both parents have Type 2 diabetes, there is a chance that nearly all of their children will have diabetes. If both parents have Type 1 diabetes, fewer than 20 percent of their children will develop Type 1 diabetes. In identical twins, if one twin develops Type 2 diabetes, the chance is nearly 100 percent that the other twin will also develop it. In Type 1 diabetes, however, only 40 to 50 percent of the second twins will develop the disease, indicating that while inheritance is important, environmental factors (for example, too much food, too much stress, viral infection, and so forth) are also involved in the development of Type 1 diabetes.

(by Diana W. Guthrie, R.N., Ph.D., and Richard A. Guthrie, M.D.)