Pathophysiology of Insulin Dependent Diabetes Mellitus

Pathophysiology of Insulin Dependent Diabetes Mellitus

The the damage done by the autoimmune attack has important physiological consequences. The destruction of beta cells compromises an individual's ability to respond to changing levels of glucose in the blood because insulin cannot be produced. Insulin has important functions in the metabolism of carbohydrate, fatty acids and amino acids. When these molecules enter the blood stream in their absorbtive state, insulin catalyzes their cellular uptake and synthesis into glycogen, triglycerides and proteins.

With regards to glucose regulation, insulin has four main functions, depending on glucose levels and cellular needs:

1. Insulin opens the glucose transport proteins (GLUT 1-5) allowing for passive diffusion of glucose into cells.

2. Insulin stimulates formation of glycogen from glucose (glycogenesis) for the purpose of storing energy in cells.

3. Insulin inhibits the breakdown of glycogen to glucose (glycogenolysis) favoring glycogen storage and reducing glucose output by the liver.

4. Glucose prevents the breakdown of glucose from amino acids (gluconeogenesis) by reducing the amount of amino acids available to the liver as well as blocking hepatic glucogeneic enzymes.