In type 1 diabetes, insulin-producing beta cells are destroyed by an autoimmune process, whereby the body’s immune system and your defense mechanism against disease and for some reason, recognize the cells as foreign instead of free , and therefore, attacks.
Type 2 diabetes are considered to have a strong genetic link, meaning that it tends to run in families. Several genes are being studied that may be related to the cause of type 2 diabetes.
Drugs such as steroids, dilantin, and others can raise the blood sugar level through a variety of mechanisms. Some other drugs, such as alloxan, streptozocin, and thiazide diuretics, are toxic to pancreatic beta cells and can cause diabetes.
Inheritance is a major cause of diabetes: if both parents have type 2 diabetes, the possibility exists that almost all of their children have diabetes. If both parents have type 1 diabetes, less than 20 percent of their children will develop type 1 diabetes. in identical twins, if one twin develops type 2, the possibility is almost 100 percent that the other two also develop.