Conventional versus intensive diabetes therapy in children with type 1 diabetes - Effects on memory and motor speed

OBJECTIVE - Severe hypoglycemia may impair medial temporal-mediated cogniti ve skills, such as the ability to recall past events explicitly (delayed de clarative memory). The objective of this study was to determine whether del ayed declarative memory deficits are present in a group of diabetic childre n with an increased. risk of severe hypoglycemia. RESEARCH DESIGN AND METHODS - Nondiabetic children (n = 16) and children wi th type I diabetes who had been randomly assigned to either intensive (IT) (n = 13) or conventional (CT) (n = 12) diabetes therapy at the lime of diag nosis participated in the study. All episodes of severe hypoglycemia were p rospectively ascertained. All children were tested on memory tasks that hav e been closely linked to medial temporal Functioning and on reaction time m easures. RESULTS - Our results demonstrated that the IT group had a threefold higher rate of severe hypoglycemia, performed less accurately on a spatial declar ative memory task, and performed more slowly but not less accurately, on a pattern recognition task than did the CT group or control subjects. In addi tion, both groups of type 1 diabetic children were significantly impaired o n a motor speed task compared with their nondiabetic peers. CONCLUSIONS - These results indicate a selective relative memory impairment associated with IT that is consistent with the effects of severe hypoglyce mia and medial temporal damage or dysfunction. If larger prospective studie s determine that severe hypoglycemia is the mediating factor for this memor y impairment, extreme caution in imposing overly strict standards for gluco se control in young patients with type I diabetes would be indicated becaus e of the increased risk of hypoglycemia associated with IT regimens.