CHILDREN living with type 1 diabetes (T1D) are increasingly recognised as being at risk of neurocognitive impairment, potentially driven by chronic exposure to glycaemic extremes. While mean HbA1c has traditionally been used to assess metabolic control, emerging evidence suggests that HbA1c variability may be a more sensitive indicator of long-term glycaemic instability and its effects on the developing brain. A new retrospective study adds to this growing body of research by demonstrating a strong association between HbA1c variability and poorer cognitive performance in paediatric patients with T1D.
Study Design
The study analysed data from 180 children with T1D treated at a tertiary care centre in Pakistan, with a mean age of 12.6 years and an average diabetes duration of nearly six years. Serial HbA1c values collected over the preceding 24 months were used to calculate glycaemic variability using standard deviation and coefficient of variation (CV). Participants were stratified into high-variability and low-variability groups using a CV threshold of 8%. Neurocognitive performance was assessed across multiple domains, including full-scale intelligence quotient (IQ), working memory, processing speed, attention, and executive function, using standardised cognitive tests.
Neurocognitive Outcomes Associated with HbA1c Variability
Children with high HbA1c variability performed significantly worse across several cognitive domains compared with those with more stable glycaemic control. Notably, full-scale IQ scores were substantially lower in the high-variability group, alongside impairments in working memory, processing speed, and executive function. HbA1c CV demonstrated the strongest negative correlation with overall IQ, suggesting that fluctuations in long-term glycaemic control may have a cumulative adverse effect on cognitive development. Importantly, multivariate analysis showed that HbA1c variability and hypoglycaemia frequency independently predicted lower IQ scores, even after accounting for mean HbA1c levels.
Clinical Implications of HbA1c Variability in Type 1 Diabetes
These findings reinforce the concept that achieving stable glycaemic control may be as important as lowering average HbA1c in paediatric diabetes management. Reducing long-term glucose variability could represent a modifiable target to preserve neurocognitive function in children with T1D. The results support closer monitoring of HbA1c trends over time and highlight the potential value of advanced diabetes technologies and tailored education strategies aimed at minimising glycaemic fluctuations.
Reference
Asfand Yar M et al. HbA1c variability as a predictor of neurocognitive decline in children with type 1 diabetes. Cureus. 2025;17(12):e99141.
