Cognitive Function is Disrupted by Both Hypo- and Hyperglycemia in School-Aged Children with type 1 diabetes: A Field Study

  1. Linda A. Gonder-Frederick, PhD. (lag3g{at},
  2. John F. Zrebiec, M.S.W1,
  3. Andrea U. Bauchowitz, PhD.2,
  4. Lee M. Ritterband, PhD,
  5. Joshua C. Magee, M.A.,
  6. Daniel J. Cox, PhD and
  7. William L. Clarke, M.D.3
  1. Behavioral Medicine Center, Department of Psychiatric Medicine and Neurobehavioral Science, Department of Pediatrics3 University of Virginia Health Sciences Center,
  2. Joslin Diabetes Center1 Harvard Medical School, Boston, Masschusetts
  3. Patton State Hospital2 Patton, California


    Objectives: Develop a field procedure using Personal Digital Assistance (PDA) technology to test the hypothesis that naturally-occurring episodes of hypo- and hyperglycemia are associated with deterioration in cognitive function in children with type 1 diabetes.

    Research Design and Methods: 61 children aged 6 to 11 with type 1 diabetes received a PDA programmed with two brief cognitive tests (mental math and choice reaction time), which they completed just before home glucose readings. The computer recorded time to complete each test and number of correct responses. Children completed several trials per day over four to six weeks for a total of 70 trials. Performance variables were compared across glucose ranges. Individual impairment scores were also computed for each child by calculating the standard deviation between performance during euglycemia and during glucose extremes.

    Results: Time to complete both mental math and reaction time was significantly longer during hypoglycemia. During hyperglycemia, time to complete math was significantly longer and reaction time was marginally significant (p = .053). There were no differences on task accuracy. Decline in mental math performance was equivalent at glucose levels < 3.0 and > 22.2 mmol/L. Individual impairment scores varied greatly across children, with no age or gender differences.

    Conclusions: A decrease in mental efficiency occurs with naturally-occurring hypo- and hyperglycemic glucose fluctuations in children with type 1 diabetes and this effect can be detected with a field procedure using PDA technology. With blood glucose levels > 22.2 mmol/L, cognitive deterioration equals that associated with significant hypoglycemia.


      • Received September 18, 2008.
      • Accepted March 7, 2009.