Acute hyperglycaemia impairs cognitive function in children with IDDM

J Pediatr Endocrinol Metab. Jul-Aug 1996;9(4):455-61. doi: 10.1515/jpem.1996.9.4.455.


Objective: The effects of acute hyperglycaemia on cognitive function in children remain controversial. This study was designed to investigate the suggestion that acute hyperglycaemia impairs cognition in IDDM children.

Design: To examine this question we studied 12 randomly selected children with IDDM (6 boys, 6 girls, mean age 12.4 years). Cognitive performance was assessed on two occasions at least six months apart (7.4 +/- 1.4 mths, range: 6.3-11.1 mths) under randomised conditions of hyperglycaemia (20-30 mmol/l) on one occasion and euglycaemia (5-10 mmol/l) on the other. Target glucose levels were achieved using a modified clamp technique with subjects and psychologist blinded to the glycaemic level. Cognitive tests chosen to assess performance skills were subtests from the Wechsler Intelligence Scale for Children-3rd Edition (WISC-111).

Results: No significant learning effect was present. However, there was a reduction in performance IQ at hyperglycaemia compared with euglycaemia (106 +/- 4.3 vs 112 +/- 4.5 IQ points respectively, p < 0.05). Under hyperglycaemic conditions the mean decrease in percentile score for performance IQ was 9.5%. Of the 12 children tested, 8 had a decrease in IQ when hyperglycaemic, which was independent of duration of diabetes and long term metabolic control assessed by HbA1c.

Conclusion: Acute hyperglycaemia results in impairment of complex cognitive function in children with IDDM. This may have important implications for school performance.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Blood Glucose / metabolism
  • Child
  • Cognition*
  • Cross-Over Studies
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / complications*
  • Female
  • Glucose Clamp Technique
  • Humans
  • Hyperglycemia / physiopathology*
  • Male
  • Wechsler Scales


  • Blood Glucose