Influence of insulin sensitivity on food cue evoked functional brain connectivity in children

Insulin resistance during childhood is a risk factor for developing type 2 diabetes and other health problems later in life. Studies in adults have shown that insulin resistance affects regional and network activity in the brain which are vital for behavior, including ingestion and metabolic control. To date, no study has investigated how brain connections during exposure to food cues are association with peripheral insulin sensitivity in children.

We included 53 children (36 girls) between the age of 7-11 years, who underwent an oral Glucose Tolerance Test (oGTT) to estimate peripheral insulin sensitivity (ISI). Brain responses were measured using functional magnetic resonance imaging (fMRI) before and after glucose ingestion. We compared food-cue task-based activity and functional connectivity (FC) between children with lower and higher ISI, adjusted for age and BMIz.

Independent of prandial state (i.e., glucose ingestion), children with lower ISI showed higher FC between the anterior insula and caudate and lower FC between the posterior insula and mid temporal cortex than children with higher ISI. Sex differences were found based on prandial state and peripheral insulin sensitivity in the insular FC. No differences were found on mean brain responses to food cues.

In response to food cues, children with lower peripheral insulin sensitivity exhibited distinctive patterns of neural connectivity, notably in the insula's functional connections, when contrasted with their counterparts with higher peripheral insulin sensitivity. These differences might influence eating behavior and future risk of developing diabetes.