HL-02: Cognitive function and brain outcomes in T1D, 30 years after diagnosis- the CLARiFY study
R Beare, A Brown, T Collyer, E Koubek, C Adamson, D Zajac, C Nicholas, C Moran, S Sakowski, V Srikanth, E A Northam, E Feldman, F J CameronAbstract
Background
Thirty years ago, newly diagnosed patients with Type 1 Diabetes (T1D) and non-T1D controls were recruited into a longitudinal study of neurocognition and brain development. The Cognition and Longitudinal Assessments of Risk Factors over 30 Years (CLARiFY) Diabetes Complications Study is the most recent component of that study.
Objectives
To assess cognition and brain microstructure and morphology in mid-adulthood in a cohort of T1D patients diagnosed during childhood.
Methods
These are fully described in BMJ Open 2025 Jun 25;15(6):e105887. At baseline, 135 youth with newly diagnosed T1D and 129 age-matched non-T1D controls were recruited sequentially between 1990-1992 and completed assessments to evaluate cognition. These participants were re-evaluated with cognitive assessments using Wechsler Abbreviated Scale of Intelligence (WASI-II) and self-reported functional health outcomes. They also underwent structural and functional MRI scans to assess brain microstructure and morphology. In the T1D group, life-time HbA1C data were collected.
Results
Data were available for 105 T1D participants, 46 original and 155 new non-T1D controls. The T1D group had significantly lower FSIQ scores (as measured by WASI-II) when compared to non-T1D controls p=<0.001 (95% CI 2.269, 7.992) adjusted for age, sex and education levels. MRI revealed reduced subcortical gray matter volume and cortical thickness in participants with T1D.
Conclusions
Significant differences are observed in both brain structure and cognition at 30 years post diagnosis in a cohort of T1D participants in comparison to non-T1D control participants.