25.4 : 糖尿病的病理生理学

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia.

The two most common types of diabetes mellitus are type 1 and type 2.

Type 1 diabetes results from autoimmune destruction of the islet β cells, caused by infiltrating immune cells. They produce inflammatory agents, destroying the β cells. Destruction of 80% of cells leads to hyperglycemia and clinical diagnosis.

Exposure to viruses or environmental agents stimulates autoimmune cellular destruction in the pancreas.

Type 2 diabetes results from heterogeneous causes.

Firstly, the impairment of the islet β cell function leads to delayed and insufficient insulin secretion.

Next, the impaired insulin responsiveness in skeletal muscles, adipose tissue, and liver impedes glucose transport from circulation.

Lastly, excessive glucagon production and the liver's resistance to insulin action dysregulates hepatic glucose metabolism and increases blood glucose levels in pre- and post-prandial states.