Context: Neurodevelopmental disorders are more prevalent in childhood-onset type 1 diabetes than in the general population, and the symptoms may limit the individual’s ability for diabetes management.

Objective: This study investigated whether comorbid neurodevelopmental disorders are associated with long-term glycemic control and risk of diabetic complications.

Methods: This population-based cohort study used longitudinally collected data from Swedish registers. We identified 11 326 individuals born during 1973-2013, diagnosed with type 1 diabetes during 1990-2013 (median onset age: 9.6 years). Among them, 764 had a comorbid neurodevelopmental disorder, including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, and intellectual disability. We used multinomial logistic regression to calculate odds ratios (ORs) of having poor glycemic control (assessed by glycated hemoglobin [HbA1c]) and Cox regression to estimate hazard ratios (HRs) of nephropathy and retinopathy.

Results: The median follow-up was 7.5 years (interquartile range [IQR] 3.9, 11.2). Having any neurodevelopmental disorder (OR_adjusted 1.51 [95% CI 1.13, 2.03]), or ADHD (OR_adjusted 2.31 [95% CI 1.54, 3.45]) was associated with poor glycemic control (mean HbA_1c > 8.5%). Increased risk of diabetic complications was observed in patients with comorbid neurodevelopmental disorders (HR_adjusted 1.72 [95% CI 1.21, 2.44] for nephropathy, HR_adjusted 1.18 [95% CI 1.00, 1.40] for retinopathy) and patients with ADHD (HR_adjusted 1.90 [95% CI 1.20, 3.00] for nephropathy, HR_adjusted 1.33 [95% CI 1.07, 1.66] for retinopathy). Patients with intellectual disability have a particularly higher risk of nephropathy (HR_adjusted 2.64 [95% CI 1.30, 5.37]).

Conclusion: Comorbid neurodevelopmental disorders, primarily ADHD and intellectual disability, were associated with poor glycemic control and a higher risk of diabetic complications in childhood-onset type 1 diabetes. © The Author(s) 2021.