The spatial heterogeneity of intra-pancreatic fat deposition in children and adolescents with obesity.

Childhood obesity is associated with an increased risk of metabolic associated fatty liver disease (MAFLD) and intra-pancreatic fat deposition (IPFD). Recent studies in adults suggest that pancreatic fat distribution is heterogeneous and that fat deposition in different regions may have distinct metabolic implications. However, data on regional IPFD patterns and their association with insulin resistance in children with obesity remain limited. This study aimed to investigate the regional distribution of pancreatic fat and its association with insulin resistance in children and adolescents with obesity. This retrospective study included 231 children and adolescents with obesity (156 boys, 75 girls; age range 8-18 years). All participants underwent magnetic resonance imaging (MRI) using the qDixon technique to quantify fat fractions in the pancreatic head, body, and tail, as well as in the liver. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Statistical analyses included Spearman correlations, logistic regression, and receiver operating characteristic (ROC) curve analysis. The prevalence of high IPFD was higher in the pancreatic head than in the body and tail across all cutoff values (> 10%, > 15%, and > 20%) in both sexes (p < 0.01). Pancreatic head fat, but not body or tail fat, was significantly correlated with insulin levels and HOMA-IR (p < 0.01). In logistic regression models adjusted for confounders, pancreatic head fat (as a continuous variable and with a > 20% cutoff) was independently associated with high insulin (odds ratio (OR) = 1.02, 95% confidence interval (CI):1.002-1.043, and OR = 2.10, 95%CI: 1.00-4.47) and insulin resistance (OR = 1.02, 95% CI: 1.002-1.044; and OR = 2.31, 95% CI: 1.13-4.78, respectively). ROC analysis showed that pancreatic head fat had a significantly higher area under the curve (AUC = 0.65) for predicting insulin resistance than body, tail and liver fat (AUC = 0.60)(p = 0.02). In children and adolescents with obesity, the deposition of pancreatic fat is heterogeneous, with the greatest accumulation observed in the pancreatic head. Fat in the pancreatic head is independently associated with high insulin resistance, whereas fat in the body and tail is not. What is Known? • Obesity is associated with an increased risk of intra-pancreatic fat deposition (IPFD). • IPFD may be associated with metabolic risk. What is New? • This is the first study reporting the spatial heterogeneity of IPFD in children and adolescents with obesity. • Fat accumulation in the pancreatic head, but no in body and tail is associated with high level of insulin resistance.