Increased GLP-1 response to oral glucose in pre-pubertal obese children

Abstract

Gastrointestinal hormones, such as glucagon-like peptide (GLP-1), have been hypothesized to play a role in the pathogenesis of obesity-related complications. However, few data are available in youth. The objective of this study was to investigate the GLP-1 response to oral glucose load in obese pre-pubertal children and its relationship with insulin secretion. Ten pre-pubertal obese children [five boys; 10.5±1.6 years; body mass index-standard deviation score (BMI-SDS): 2.2±0.5] and 10 controls (eight boys; 9.9±1.2 years; BMI-SDS:-0.7±0.5) underwent a modified oral glucose tolerance test (OGTT) to evaluate post-load glucose, insulin and GLP-1 responses. Insulin sensitivity [homeostasis model assessment of insulin resistance (HOMA-IR), whole body insulin sensitivity index (WBISI)] and secretion [HOMA-beta, insulinogenic index (IGI)] indexes, area under the curve (AUC) for glucose, insulin and GLP-1 were calculated. In obese children GLP-1 AUC values were higher and correlated with BMI-SDS (r=0.45; p=0.04), HOMA-IR (r=0.53; p=0.01) and fasting glucose (r=0.68; p=0.001). Obese children showed an increased GLP-1 response to oral glucose. These changes might likely represent a compensatory mechanism to avoid post-prandial hyperglycemia and allow a normal glucose tolerance.