Chinese Association of Idaho State University (CAISU)
Diabetes is a chronic condition characterized by the presence of high levels of blood glucose (hyperglycemia) that is caused by the impaired function of insulin. Insulin is the hormone produced by the pancreas that allows glucose to enter the cells and be used as an energy source. When this mechanism is impaired, glucose accumulates in the bloodstream.
Approximately 10% of diabetics suffer from this type of the disease that usually occurs in childhood or adolescence. In type 1, the pancreas produces no insulin, because of the destruction of beta cells that secrete this hormone, so the patients need insulin injections every day for a lifetime. The rate of destruction of beta cells, however, is quite variable, so the onset of the disease can be rapid in some people, (usually in children and adolescents) and slower in others (adults).
The cause of type 1 is not fully understood, but the most probable cause is the presence of antibodies in the blood that attack the antigens of the insulin-producing cells. This damage, which induces the immune system against the insulin-producing cells, could be linked to environmental factors (such as dietary factors) or genetic factors (a general predisposition to react to external phenomena including viruses and bacteria). In fact, studies in monozygotic twins have shown that the risk that one twin will develop type 1 diabetes is 30-40%, if the other twin already suffers from the disease. One could, therefore, inherit a predisposition to the disease through the transmission of genes affecting the immune system and causing a reaction not only towards common infectious agents, but also towards the beta cells of the pancreas. This abnormal immune response causes the progressive destruction of beta cells, so insulin can no longer be produced, which causes diabetes.
It is the most common form of diabetes, representing about 90% of cases. The cause is still unknown, although it is certain that the pancreas has the ability to produce insulin, but the body's cells do not manage to use it effectively. Typically, it takes 30-40 years for the disease to fully develop and many risk factors have been associated with its onset. These factors include: family history, lack of exercise, being overweight and belonging to certain ethnic groups. As far as family history is concerned, about 40% of diabetics have first degree relatives (parents, siblings) affected by the disease, suggesting a strong hereditary component to this type diabetes.