Final answer:
Insulin-dependent diabetes mellitus (IDDM), or type 1 diabetes, is caused by the destruction of the beta cells in the pancreas, while insulin resistance is the underlying pathophysiology of non-insulin-dependent diabetes mellitus (NIDDM), or type 2 diabetes.
Step-by-step explanation:
Type 1 diabetes, also known as insulin-dependent diabetes mellitus (IDDM), is caused by the destruction of the beta cells in the pancreas. This destruction is typically the result of an autoimmune response, where the body's immune system mistakenly attacks and destroys the beta cells. As a result of this destruction, the beta cells are unable to produce insulin, leading to a deficiency of insulin in the body. Without insulin, glucose cannot enter the cells and remains in the bloodstream, resulting in high blood sugar levels.
On the other hand, type 2 diabetes, also known as non-insulin-dependent diabetes mellitus (NIDDM), is primarily characterized by insulin resistance. In this condition, the cells of the body become less responsive to insulin, making it difficult for glucose to enter the cells. As a result, the body's cells are unable to effectively use glucose for energy, leading to elevated blood sugar levels.