Negative effect of acute hypoglycaemia on memory in adolescents with type 1 diabetes

Researchers from the Faculty of Medicine and the Faculty of Arts at the University of Ljubljana found a reduction in spatial working memory capacity in adolescents with type 1 diabetes (T1D) in comparison to healthy peers during acute hypoglycaemia, while there were no statistically significant differences between the two groups when blood sugar levels were normal.

Children with T1D experience mild cognitive changes in comparison to healthy peers. The reasons for this are not yet known. The objective of the researchers from the Faculty of Medicine of the University of Ljubljana (Jasna Šuput Omladič (lead author), Dr. Andrej Vovk, Prof. Dušan Šuput, Asst. Prof. Klemen Dovč, Assoc. Prof. Nataša Bratina, Asst. Prof. Magdalena Avbelj Stefanija, Prof. Tadej Battelino (corresponding author)) and the Faculty of Arts of the University of Ljubljana (Dr. Anka Slana Ozimič) and Prof. Grega Repovš was to investigate the effect of acute hypoglycaemia on brain function in adolescents with T1D.

The study took the form of an open clinical study. It included 20 participants with T1D (aged 14.64 ± 1.78 years) and 20 age-matched healthy control subjects (aged 14.40 ± 2.82 years). All participants underwent structural MRI and completed two functional MRI sessions. Participants with T1D completed the first functional MRI session with a normal blood sugar concentration and the second with a blood sugar concentration increased by 20 mmol/L; blood sugar concentration was not changed in the control group.

In comparison to healthy peers, a reduction in spatial working memory capacity occurred in the group with T1D during acute hypoglycaemia. When blood sugar values were normal there was no statistically significant difference between the two groups. As far as the researchers are aware, this is the first study to look at brain activation during acute hypoglycaemia.

Acute hypoglycaemia negatively affects spatial working memory capacity in adolescents with T1D. This may be because of poorer brain activation during the stimulus-encoding phase. Reduced spatial working memory capacity is relevant for daily functioning and can affect the academic performance of this age group.

Using advanced MRI techniques and spectroscopy, the authors also indicated the most probable cause of impaired brain function, since they observed a reduction in the concentration of all measured metabolites in brain tissue, which points to the formation of micro-oedemas in the brain caused by hypoglycaemia.

Reference: ŠUPUT, Jasna, SLANA OZIMIČ, Anka, VOVK, Andrej, ŠUPUT, Dušan, REPOVŠ, Grega, DOVČ, Klemen, BRATINA, Nataša, AVBELJ, Magdalena, BATTELINO, Tadej. Acute hyperglycemia and spatial working memory in adolescents with type 1 diabetes. Diabetes Care, ISSN 0149-5992, Aug 2020, Vol. 43, No. 8, pp. 1941–1944.