Conclusions Several cross-sectional studies have shown an association between severe hypoglycemia and cognitive impairment in patients with type I diabetes. It is striking, however, that the impairments that have been registered are modest and mostly concern decision-making speed. Cross-sectional studies can show correlations but never determine causality. As a consequence, it is conceivable that patients who find it difficult to make fast decisions develop severe hypoglycemia because they are unable to take adequate measures to ward off the danger in time. It cannot be excluded, however, that hypoglycemia with unconsciousness in this group of patients who develop hypoglycemia in the absence of intensive insulin therapy causes neuropsychological deficits.
Hypoglycemic coma causes brain damage in rats.
Two long-term, prospective, randomized studies have shown that during intensified insulin treatment, the risk of hypoglycemia increases, but there is no increase in cognitive impairment. Patients with advanced neuropathy or serious retinopathy may be more vulnerable, and these patients should have glycemic goals that make it possible to avoid severe hypoglycemia. Children before puberty are also probably vulnerable to deleterious effects of hypoglycemia on the brain. Therefore, slightly higher glycemic goals should be set for these young patients. Generally, the present trend toward more intensive diabetes management and lower blood glucose levels in adults with type I diabetes should not be halted because of fear of hypoglycemia, but patients need experienced tutors.