ADHD should be considered in adolescents with type 1 diabetes and poor metabolic control

Abstract

To the Editor: We read with interest the paper by Liu et al recently published in Diabetologia: ‘Poor glycaemic control is associated with increased risk of neurodevelopmental disorders in childhood-onset type 1 diabetes: a population-based cohort study’ [1]. The subject concerns an important area in general paediatrics, neuropaediatrics, paediatric endocrinology and child neuropsychiatry. The authors report data from health registers in Sweden from 1973 to 2013, and the study cohort encompasses 8430 patients with childhood-onset type 1 diabetes, with a median age of diabetes onset of 9.6 years. Data were compared with 84,300 reference individuals. The main findings from the study were that the risk of any neurodevelopmental disorders (attention-deficit/hyperactivity disorder [ADHD], autism spectrum disorder [ASD] and intellectual disability) were statistically higher among patients with childhood-onset type 1 diabetes. In particular, the risk of ADHD increased with HbA1c levels, and the highest risk was observed in patients with mean HbA1c > 8.6% (>70 mmol/mol). The authors discuss several possible mechanisms that m igh t exp l a i n t h e obse rved i nc r e a s ed r i s k o f neurodevelopmental disorders in patients with type 1 diabetes and poor glycaemic control, such as inadequate growth of grey and white matter microstructure and volume alterations in different areas of the brain. As mentioned by the authors, it has previously been reported that compromised brain growth and neurodevelopment in type 1 diabetes may lead to altered neuropsychological functions. Importantly, the authors also discuss that ‘patients with type 1 diabetes with undiagnosed neurodevelopmental disorders may have inferior neuropsychological functions that can negatively affect their abilities to manage their diabetes, resulting in poor glycaemic control.’ In a study from Australia [2], the authors discussed that, on one hand, different potential dysglycaemic insults to the brain may cause cellular and structural injury and lead to altered neuropsychological outcome. On the other hand, they emphasised that impaired executive function and mental health, in turn, could affect patients’ adherence and the ability to make adaptive lifestyle choices. This means that impaired executive functioning creates a potential feedback loop of diabetic dysglycaemia leading to brain injury, further impaired executive function and mental health, which results in suboptimal adherence and further dysglycaemia. In a prospective study with neurocognitive follow-up, adolescents with type 1 diabetes were found to be at high risk for psychiatric disorders [3]. Poorly controlled diabetes over the first 10 years of illness was associated with pre-existing behaviour problems at diagnosis. In our own clinical studies of children and adolescents with type 1 diabetes, we found that both executive problems [4] and ADHD were associated with high HbA1c [5]. ADHD is a clinical diagnosis with early onset, and when the children in the study by Liu et al [1] were diagnosed with * Charlotte Nylander [email protected]