Our health care team seems to think that if blood glucose is high for less than four hours, there is no physiological harm done. The practical application of this idea would be that if my son tests himself frequently and takes a bolus to bring himself down that this will avoid the long term complications of diabetes. I would like to better understand the physiology of this theory.

I realize that the tighter control, the better the long term outcome, but I don’t fully understand what happens to the body’s cells when blood glucose is high due to lack of insulin to transport the glucose into the cells other than that the cells starve for lack of energy. I also do not understand the four hour time period or what is or is not occurring during this small window of opportunity.

I think that The ‘four hour’ advice is just a catchphrase to encourage frequent testing. I am sure that your diabetes team would agree that what really counts towards complications is both the level of blood glucose above normal as well as the duration over which abnormal levels are sustained. The measure of this is of course the hemoglobin A1c.

You obviously understand the implication that high blood glucose levels, especially when they are accompanied by ketone production, mean an interference with basic energy needs. The other consequence of continued high blood glucose levels are that serum proteins get an excessive number of glucose molecules attached to them. This ultimately not only deforms the structure of the molecule but alters its function. These Advanced Glycation End products (AGEs) can then become attached to specific receptors on the walls of blood vessels where they then provoke further degenerative changes in the blood vessels. Nowadays, there are several treatments that are thought to prevent and reverse these processes such as giving folic acid to reduce homocysteine levels.

DOB