Enhanced oral glucose tolerance test for early detection of insulin resistance and metabolic complications in children with obesity

Abstract

Background and aims

Early detection of insulin resistance (IR) and obesity-related complications is crucial for preventing type 2 diabetes. This study aimed to identify dynamic metabolic biomarkers for more precise early detection of IR and metabolic abnormalities.

Methods

This cross-sectional cohort study evaluated IR and metabolic biomarkers in 403 children with obesity (median age 13.18 years, 51.3 % female, 98.5 % with obesity) using an enhanced oral glucose tolerance test (eOGTT). IR was assessed via four indices, with the Matsuda Insulin Sensitivity Index (ISI-M) used as the primary measure. Participants were stratified into quartiles based on ISI-M.

Results

Participants with the highest IR (Q1) were older (p = 0.002), had a higher body mass index, were in a more advanced pubertal stage (p < 0.001), and had significantly elevated glucose and insulin levels (p < 0.001 for both) compared to the most insulin sensitive (Q4), with significant differences observed across all quartiles (p < 0.050 for all). Insulin at 120 min demonstrated excellent diagnostic accuracy for IR (AUC=0.958). Triglyceride levels in Q1 showed minimal decline during the eOGTT, while greater declines were observed with increasing insulin sensitivity (p = 0.002 across quartiles), suggesting that a lack of decline in triglycerides may help identify IR. High-sensitivity C-reactive protein levels increased with IR (p = 0.024). Baseline beta-hydroxybutyrate levels were highest in the Q4 and showed the greatest absolute decrease during the eOGTT, compared to Q1 (p < 0.001 for both).

Conclusions

We validated established IR markers in children with obesity, while demonstrating that eOGTT may offer improved characterization and earlier identification of those at risk for metabolic complications.