Academic abilities and glycaemic control in children and young people with Type 1 diabetes mellitus

Aims To determine if children and young people aged < 23 years with Type 1 diabetes differ in academic ability from age‐matched control subjects without Type 1 diabetes and whether academic scores are related to glycaemic control. Methods Using a cross‐sectional study design, we administered cognitive and academic tests (Woodcock‐Johnson III Spatial Relations, General Information, Letter‐Word Recognition, Calculation and Spelling tests) to young people with Type 1 diabetes ( n =61) and control subjects ( n =26) aged 9–22 years. The groups did not differ in age or gender. Participants with Type 1 diabetes had a disease duration of 5–17.7 years. History of glycaemic control (HbA 1c , diabetic ketoacidosis and severe hypoglycaemic episodes) was obtained via medical records and interviews. Results The participants with Type 1 diabetes had a lower mean estimated verbal intelligence ( IQ ) level compared with those in the control group ( P =0.04). Greater exposure to hyperglycaemia over time was associated with lower spelling abilities within the group with Type 1 diabetes ( P =0.048), even after controlling for age, gender, socio‐economic status, blood glucose level at time of testing and verbal IQ ( P =0.01). History of severe hypoglycaemia or ketoacidosis was not associated with differences in academic abilities. Conclusions In children and young people, Type 1 diabetes was associated with a lower verbal IQ . Moreover, increased exposure to hyperglycaemia was associated with lower spelling performance. These results imply that hyperglycaemia can affect cognitive function and/or learning processes that may affect academic achievement.