Changes in attention with hypo- and hyperglycaemia in children with insulin dependent diabetes mellitus

We compared the results of a computerized attention test (TOVA) in 38 children with insulin dependent diabetes mellitus in relation to various spontaneously occurring blood glucose levels. Testing was performed at the following blood glucose levels: <3.3 mmol/1 (hypoglycaemia), 3.3-8.3 mmol/1 (normoglycaemia) and >8.3 mmol/1 (hyperglycaemia). The attention (sum of errors and response time) varied significantly with the blood glucose level (P = 0.002). The highest number of errors of omission and the longest response time was observed during the test run with hypoglycaemia. Age, sex, age at manifestation of the disease, metabolic control and the results of the intelligence test had no significant influence on these results. We found that attention in children with diabetes was significantly reduced compared to TOVA norms especially during mild hypoglycaemia (P < 0.001). Irrespective of the blood glucose levels, reaction time and the variability of the reaction time differed significantly between TOVA norms and diabetic children (P < 0.01). CONCLUSION: In children with diabetes mellitus a significant reduction in attention was found at mild hypoglycaemia but as well at low normal blood glucose levels. Attention deficits due to transient lowering of blood glucose may therefore occur in diabetic children even before they are aware of hypoglycaemic symptoms.