Impact of dysglycemia and obesity on the brain in adolescents with and without type 2 diabetes: A pilot study

Objective Both diabetes and obesity can affect the brain, yet their impact is not well characterized in children with type 2 (T2) diabetes and obesity. This pilot study aims to explore differences in brain function and cognition in adolescents with T2 diabetes and obesity and nondiabetic controls with obesity and lean controls. Research design and methods Participants were 12-17 years old (5 T2 diabetes with obesity [mean HgbA1C 10.9%], 6 nondiabetic controls with obesity and 10 lean controls). Functional MRI (FMRI) during hyperglycemic/euglycemic clamps was performed in the T2 diabetes group. Results When children with obesity, with and without diabetes, were grouped (mean BMI 98.8%), cognitive scores were lower than lean controls (BMI 58.4%) on verbal, full scale, and performance IQ, visual-spatial and executive function tests. Lower scores correlated with adiposity and insulin resistance but not HgbA1C. No significant brain activation differences during task based and resting state FMRI were noted between children with obesity (with or without diabetes) and lean controls, but a notable effect size for the visual-spatial working memory task and resting state was observed. Conclusions In conclusion, our pilot study suggests that obesity, insulin resistance, and dysglycemia may contribute to relatively poorer cognitive function in adolescents with T2 diabetes and obesity. Further studies with larger sample size are needed to assess if cognitive decline in children with obesity, with and without T2 diabetes, can be prevented or reversed.