Understanding Type 1 Diabetes: Causes and Insulin Dependence

The correct answer is destruction of islet cells.

Insulin dependent diabetes mellitus (IDDM), also known as type 1 diabetes, is caused by the destruction of islet cells in the pancreas. This destruction is typically caused by an autoimmune reaction, in which the body's immune system attacks and destroys its own tissues. In the case of IDDM, the immune system attacks and destroys the islet cells in the pancreas, which are responsible for producing insulin. Insulin is a hormone that helps the body convert glucose (sugar) into energy. Without insulin, the body cannot use glucose for energy and blood sugar levels can become dangerously high.