Evidence suggests that the timing of diabetes onset and exposure to serious hypoglycemia may be factors in the cognitive decline of type 1 diabetics…
The new study is the first of its kind to follow intelligence quotient (IQ) in type 1 diabetes patients from diagnosis in childhood into young adulthood has shown that the condition can affect some aspects of IQ.
The findings show evidence of a selective impact on specific disease risk factors on IQ. For example, diagnosis with type 1 diabetes at an earlier age was associated with a decline in visuospatial aspects of IQ, while hypoglycemic seizures, but not hyperglycemia, appear to affect verbal IQ. These associations are not novel researchers acknowledged, “We know that years after diagnosis, young people with type 1 diabetes show lower IQ, particularly if they were diagnosed before age 5 and/or have hypoglycemic seizures.”
Dr. Lin and colleagues prospectively followed 95 patients with confirmed diagnosis of type 1 diabetes compared to healthy controls. The study design was unique because it was the first to follow children periodically from time of diagnosis, as well as following healthy participants recruited at the same time. At the final follow-up, those with type 1 diabetes and healthy control had a mean age of 21.3 years.
The most significant findings in the study were that young people with type 1 diabetes exhibited lower verbal IQ and full-scale IQ in the 12 years following diagnosis compared to the healthy children. Overall, the mean change in verbal IQ was -7.81 and in full-scale was -6.42. In healthy participants the mean change in verbal IQ was -6.46 and in full-scale was -5.58. For those with early-onset diabetes, the declines were even greater, with a mean change in verbal IQ over 12 years of -10.52 and in full-scale IQ of -11.38. Similarly, in patients with a history of hypoglycemia, the mean changes were -11.02 in verbal IQ and -7.10 in full-scale IQ. The negative impacts of severe hypoglycemia on language-skills development has been reported by other researchers, but the reasons for this association remains unknown.
The researchers recommend more frequent assessment of IQ in children with diabetes. With more frequent assessments in the youth with type 1 diabetes, there may be more information to help clarify the timing and trajectory of functional and structural brain changes to optimize interventions. Ultimately, these findings may help identify specific young patients who are are more risk of particular deficits.
- First study to follow intelligence quotient (IQ) in type 1 diabetes patients from diagnosis in childhood into young adulthood has shown that the condition can affect some aspects of IQ.
- Findings suggest diagnosis with type 1 diabetes at an earlier age was associated with a decline in visuospatial aspects of IQ.
- More frequent assessment of IQ in children with diabetes may help clarify the timing and optimize interventions in this select population.
Lin A. et al. Risk factors for decline in IQ in youth with type 1 diabetes over the 12 years from diagnosis/illness onset. Diabetes Care. 8 Dec 2014. Web. 17 Dec 2014. http://care.diabetesjournals.org/content/early/2014/12/02/dc14-1385.abstract