December 9, 2021
It is difficult enough for a typical child to manage type-1 diabetes. For a child that also has ADHD, with learning difficulties, attention and memory problems, and limitations in social communication, it can be all the more challenging to carry out the complex tasks necessary to maintain glycemic control (control of blood sugar levels) and avoid diabetic harm.
To explore the additional risk associated with ADHD among children with type-1 diabetes, an international research team used the Swedish national registers to conduct a nationwide population study. Sweden has a single-payer national health insurance system, and assigns unique personal identification numbers to all residents, making it easy to cross-reference through various population and health registers.
The team used the Swedish Diabetes Register to identify all individuals born in Sweden from 1973 onwards with childhood-onset type 1 diabetes diagnosed before age 18. They then restricted the cohort to those who had no diabetic complications at diagnosis and whose HbA1c values had been recorded within 5 years of diagnosis.
Also known as the glycated hemoglobin test, HbA1c is an indicator of the average blood sugar (glucose) level over the past three months. When glucose builds up in the blood, it binds to the hemoglobin in red blood cells. The HbA1ctest measures bound glucose. Since red blood cells live for about 3 months, the test shows the average blood glucose over that period.
The team also searched for records of diabetes-related kidney damage (nephropathy) and damage to the retina (retinopathy). Diabetic retinopathy is the leading cause of blindness among working-age adults.
The nationwide cohort consisted of 11,326 Swedish youths diagnosed with type-1 diabetes, of whom 415 (3.7%) were also diagnosed with ADHD.
Poor glycemic control, defined as mean HbA1c greater than 8.5%, was found in 38% of those with ADHD, twice the 19% found in those without neurodevelopmental disorders. After adjusting for confounders(sex, age at diabetes diagnosis, year of birth and year of diabetes diagnosis, another psychiatric morbidity, parental highest education level, parental psychiatric morbidity, smoking status, mean BMI [body mass index], and mean systolic and diastolic blood pressure), those with ADHD were 2.3 times as likely to have poor glycemic control.
Patients with ADHD were also almost twice as likely to suffer kidney damage, after adjusting for sex, age at diabetes diagnosis, year of birth, year of diabetes diagnosis, another psychiatric morbidity, parental highest education level, parental psychiatric morbidity, mean HbA1c levels, mean BMI, systolic and diastolic blood pressure, and smoking status.
After the same adjustments, patients with ADHD were found to be a third (33%) more likely to suffer retinal damage.
The team concluded, "childhood-onset type 1 diabetes patients with neurodevelopmental disorders, especially those with ADHD or intellectual disability, are more prone to poor glycemic control and a higher risk of chronic diabetic complications compared with those without neurodevelopmental disorders.
Further longitudinal studies with a more comprehensive evaluation of diabetes management and molecular data are needed to provide insight into potential mediators in the association between comorbid neurodevelopmental disorder and diabetes complications in type 1 diabetes."
Shengxin Liu, Ralf Kuja-Halkola, Henrik Larsson, PaulLichtenstein, Jonas F. Ludvigsson, Ann-Marie Svensson, Soffia Gudbjörnsdottir, Magnus Tideman, Eva Serlachius, and Agnieszka Butwicka, "NeurodevelopmentalDisorders, Glycemic Control, and Diabetic Complications in Type 1 Diabetes: a Nationwide Cohort Study," The Journal of Clinical Endocrinology &Metabolism(2021), Vol. 106, No. 11, e4459-e4470, published online,https://doi.org/10.1210/clinem/dgab467.