The Effect of Poor Glycemic Control on Cognitive Function in Children and Adolescents with Type 1 Diabetes Mellitus: A Single-center Cross-sectional Study (2019-2020)

Objectives: To investigate the effect of chronic hyperglycemia, hypoglycemia, and diabetic ketoacidosis (DKA) on the cognitive function of children and adolescents with type 1 diabetes mellitus (T1DM), and explore whether early disease onset correlated with cognitive impairment.

Methods: Children and adolescents with T1DM who attended the Pediatric Diabetes Clinic between January 2019 and 2020, aged between 5-14 years, with a mean of 3 glycated hemoglobin (HbA1c) readings ≥7% (53 mmol/mol) during the study period reflecting a hyperglycemic status and who agreed to participate were interviewed about their history of hypoglycemia and DKA. Participants were personally interviewed by a clinical psychologist to assess their cognitive function using a validated Arabic version of the Stanford-Binet test.

Results: Higher mean HbA1c levels were associated with cognitive dysfunction in three verbal domains: fluid reasoning, quantitative reasoning, and working memory. Frequent hypoglycemia negatively affected verbal knowledge. In contrast, significant hypoglycemia affected both verbal and nonverbal domains of cognition, specifically verbal and nonverbal fluid reasoning, knowledge, and working memory. Children with recurrent DKA performed below average in nonverbal fluid reasoning tasks. Additionally, moderate or severe DKA, regardless of its frequency, affected children's overall intelligence quotient.

Conclusion: Regardless of disease onset, exposure to glycemic variability subjects children and adolescents to subtle and measurable cognitive dysfunction resulting in significant morbidity.