Diabetes:
how it develops:
Normally when food is absorbed from the gut, the blood sugar increases. Muscle and fat cells need that sugar in order to produce and store energy. But the blood sugar cannot get into the muscle and fat cells until the "sugar doorway" at the cell surface is unlocked. The key that unlocks the lock on the sugar door (we call that "lock" the "insulin receptor") is the insulin molecule, which is made and released into the blood by the pancreas.
When the fat cells get big and they stretch, the insulin receptor no longer functions the way it should. It's like the insulin receptors (the sugar door locks) become jammed, so that they resist the insulin key. So the blood sugar cannot get into the cells, and is stuck out in the blood stream. Too much sugar in the blood is called "hyperglycemia."
So even though the cells need sugar, the blood sugar stays high. So the pancreas works even harder, producing more and more insulin, trying to overcome the "insulin resistance" of the fat and muscle cells. "Pre-Diabetes" is a condition with high insulin levels due to this overproduction of insulin by the pancreas. Even before diabetes develops, high levels of insulin promote plaque buildup in the arteries. (1)
Eventually when the pancreas can no longer keep up, it burns out, and insulin production slows down, causing "Type 2 diabetes" as blood sugars rise. Type 1 diabetes occurs when pancreatic insulin production ceases. Type 1 diabetes can develop slowly in adults, resulting from years of poorly controlled type 2 diabetes, or it can develop more quickly in children and young adults, resulting from a viral infection causing the pancreas to stop producing insulin.
Although the risk of CV events in diabetics has improved in recent years, diabetics still have double the rate of cardiovascular disease compared with non-diabetics (2).
references:
- DECODE Study Group. Lancet. 1999;354:617-621
- Fox CS, et al. Trends in cardiovascular complications of diabetes. JAMA. 2004;292:2495-249