Children who have type 1 diabetes are at a greater risk for developing neurology development disorders, also known as neurodevelopmental disorders, and the risk is even greater for those with a high HbA1c, according to a new study.
Earlier research has indicated a possible link between childhood-onset type 1 diabetes and a higher risk that these children might develop neurodevelopmental disorders. The authors of the new study, which was published in the journal Diabetologia, were particularly interested in finding out if there is any possible connection to high blood sugar. The disorders that particularly concerned them were attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD) and intellectual disability. These disorders commonly begin in childhood, as does type 1 diabetes, which suggests a possible connection.
The authors said the origins of neurodevelopmental disorders are often attributed to genetic factors, but, they argued, “a different biological mechanism may be more plausible in type 1 diabetes.” In an earlier study they had found that children with childhood-onset type 1 diabetes had a significantly increased risk of neurodevelopmental disorders but their otherwise healthy siblings did not, which suggested that diabetes-related factors might play more important roles in the development of neurodevelopmental disorders than shared genetic and environmental influences.
The researchers collected data from 40 years of Swedish health registers (1973-2013) and identified children born with childhood-onset type 1 diabetes who had had an HbA1c measurement (an indicator of blood sugar control over the two or three months before the test) within one year of being diagnosed. Each subject was randomly matched with 10 people without diabetes from Sweden’s Total Population Register. The researchers identified neurodevelopmental disorders from Sweden’s National Patient Register, as well as other Swedish databases. Although they concentrated on attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD) and intellectual disability, they also considered certain psychiatric problems, such as anxiety, mood disorders, psychotic disorders, eating disorders and psychoactive substance misuse. In all, the researchers collected data on 8,340 people who had been diagnosed with type 1 diabetes before they were 18. They compared this group to 84,300 matched individuals without diabetes. The median follow-up was 5.6 years.
High blood glucose in T1D linked to neurodevelopomental disorders
During the follow-up period, 4.7% of the diabetes group received at least one diagnosis of a neurodevelopmental disorder, compared to 3.6% of the reference group. As the researchers wrote, “After adjustment for covariates…, individuals with childhood-onset type 1 diabetes were at statistically significantly higher risk of any neurodevelopmental disorders.”
The researchers also determined that blood sugar control was an important factor. Diabetes patients who had an HbA1c of less than 7.5% “did not show an increased risk for any neurodevelopmental disorder,” while those with an HbA1c between 7.5% and 8.6% did show a higher risk, and those with an HbA1c above 8.6% showed the highest risk of all. The researchers also reported that children with an HbA1c between 7.5% and 8.6% did not show a higher risk for autism spectrum disorders and intellectual disability, but those with an HbA1c greater than 8.6% were at an increased risk for those two conditions. In sum, the researchers said, “poor glycemic control, which was assessed using time-varying HbA1c, was an independent risk factor for subsequent neurodevelopmental disorders in childhood-onset type 1 diabetes.”
The major takeaway from the study is the importance of blood sugar control. As they explained, “Our findings suggest that maintaining adequate glycemic control is important for controlling potential psychological burdens in childhood-onset type 1 diabetes, since patients with adequate glycemic control showed no statistically significant difference in risk of any neurodevelopmental disorders compared with the general population. Notably, risks of any neurodevelopmental disorders and ADHD gradually increased at higher glycemic control, and nearly doubled in patients with poor glycemic control compared with their peers without Ttype 1 diabetes. Their advice: “…optimal diabetes management along with psychological care is crucial for children and adolescents with type 1 diabetes. Pediatricians should be aware of the relationship between treatment adherence in individuals with type 1 diabetes and impairment in executive functions.”
Want to learn more about raising a child with type 1 diabetes? Read “The Type 1 Diabetes Diagnosis” and “Type 1 Diabetes at School: What Personnel Need to Know.”