The objective of this study is to confirm the potentially detrimental effects of mild hypoglycemia on cognitive function in children with insulin dependent diabetes (IDDM), which has been suggested from previous work. The study is designed to explore differences between children and adults and males and females with and without IDDM. The effects of prior glycemic control will be assessed. In addition, pathophysiologic mechanisms that may be associated with cognitive changes during hypoglycemia will be evaluated. A correlation between alterations in cerebral blood flow and cognitive changes during hypoglycemia will be sought. The effects of epinephrine infusion and adrenergic blockade on cognitive function and cerebral blood flow will be examined. The population to be studied will consist of 70 children and adults with IDDM and 30 adult and adolescent healthy control subjects. Attempts at improvement of glycemic control in patients with IDDM is associated with an increased incidence of hypoglycemic episodes. Mild, often unrecognized, hypoglycemia is probably far more frequent that is generally accepted. If these episodes, despite being transient, have cumulative effects, this could impair school functioning and ultimate academic achievement. If significant cognitive changes are confirmed on a large scale study of children, this potential side effect of tightened glycemic control will have to be weighed into the cost: benefit ratio of attempts to prevent the chronic complications of IDDM. Recognition of patients at risk and a better understanding of the mechanisms of cognitive changes, may allow the development of future strategies that might avoid this complication while still achieving the overall goals of diabetes therapy.
