November 10, 2000
Hyperglycemia and DKA
Question from Missouri, USA:
I’ve had type 1 diabetes since childhood, and I’m wondering about the effects of hyperglycemia on the brain. I’m very interested in how it affects mood, thought processes and memory. I’ve found that since hemoglobin A1c bonds with more glucose with higher blood glucose levels, and that just like any hemoglobin, hemoglobin A1c transports oxygen from the lungs to the rest of your body, including the brain. I’ve found that oxygen deprivation causes many symptoms similar to those felt during hyperglycemia such as hindered eyesight (especially night vision), headaches, lightheadedness and hindered thinking. I’m intrigued that certain side effects caused by high blood sugar may be associated with hypoxia.
My biggest stumbling block has been the lack of research and concrete studies on hyperglycemia in relation to hypoxia. Who knows, maybe I may be onto something new and exciting!
Answer:
Your ideas touch on some fairly complicated biochemistry, but let me try to make two small contributions.
Very little work has been done on the question as to whether glycosylation of hemoglobin interferes with the amount of oxygen it can carry. Such as there has been shows that glycosylation slightly increases the affinity for oxygen, but it also slightly reduces the dissociation in the capillaries. In short, a high A1c does not affect the oxygen delivery capacity of the circulating blood.
Hyperglycemia in type�1A diabetes is due to insulin deficiency: Without insulin, glucose is prevented from getting into the cells where (like oxygen) it plays a vital role in the production of energy for all metabolic processes.
Put rather briefly, both oxygen shortage and lack of glucose in the cells both interfere with the production of energy, and in turn result in some of the symptoms you describe.
DOB
