Hyperbaric effects on glycemia

The answer is yes! There is extensive research being conducted by hyperbaric units all over the country about this very thing. There is a direct correlation between a patient's glucose level and their seizure threshold in the hyperbaric environment.
Hyperbaric treatments on average lower a patient's glucose level by 50 mg/dl. It is very important that the patient eat a good meal and have their glucose level checked before and after the hyperbaric treatment. If the patient is very brittle I have seen glucose levels drop by 100 mg/dl while receiving treatment. If the glucose level drops too low, the patient may experience a diabetic seizure while in the chamber.
There is a chapter about the suppositions on hyperbaric effects on glucose in the textbook on hyperbaric nursing, edited by Valarie Larson-Lohr.

Hope I helped.