High blood glucose is HYPERglycemia not HYPOglycemia. Through your description of diabetes, you focus on the response to insulin. Try to think of diabetes with the level of blood glucose as the variable to be controlled.
As we eat, nutrients are converted to glucose. Glucose (or dextrose) is the active ingredient in corn syrup, so this is a quick injection into the circulation. Parts of starches, amino acids, and fats can be converted into glucose if they aren't used for other things. Avoiding sugar, therefore, doesn't mean you run without glucose, you just change the rate glucose enters the system.
Insulin is released in response to hyperglycemia. Not all cells need insulin to use sugar (the heart, the brain, muscle), but storage locations (liver, fatty tissue) do. Regular excercise becomes a glucose sink by moving that sugar into the muscles to produce energy. Mental activity also uses a fair amount of sugar!
The effect of insulin is countered by glucocorticoids. These are released in response to stressful conditions. They get the body ready for fight or flight and cause the release of sugar into the blood. These two hormones regulate glucose levels in the blood and are supposed to cross regulate each other. Like any control system, steady state operations can disturbed and the system is challenged to recover. When it can't, chronic hyperglycemia produces the symptoms of diabetes.
Before the 1920's a diagnosis of diabetes was a death sentence. As medical science extended the life of diabetic individuals, long term effects of the disease on every system in the body begain to show.
Older individuals trying to relate a family medical history may recall a parent or grandparent died of heart disease or kidney disease and these may have been the result of undiagnosed diabetes back in the day. On the otherhand, way back when, before antibiotics and with wars (when life expectency was less than 65 years), diabetes may not have manifested. My point is this: diabetes may not be spreading in the population, it may have been with us all along.
I know discussion on the topic was closed yesterday, but had to address the correction...then I got carried away I guess!
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