MON-233 - Metformin Treatment in Pediatric Obesity: A Real-World Experience Showing Pronounced 6-Month Improvement but Limited Long-Term Sustainability

Background: Metformin is widely used in pediatric obesity to improve insulin resistance, yet real-world data remain confounded by baseline disease severity.

Objective: To evaluate whether metformin modifies metabolic trajectory or reflects baseline severity in obese adolescents.

Methods: Ninety-six obese adolescents (32 metformin-treated, 64 untreated) were retrospectively evaluated at baseline, 6 months, and 12 months. Anthropometric, biochemical, and OGTT-derived glucose and insulin parameters were analyzed. Insulin resistance was assessed using HOMA-IR and OGTT indices. Analyses included between-group comparisons, within-group longitudinal changes, sex-stratified analysis, ANCOVA (adjusted for age, sex, baseline values), and mixed-effects modeling.

Results: At baseline, the metformin group had significantly higher BMI, fasting insulin, HOMA-IR, HbA1c, and uric acid (all p< 0.01), indicating greater metabolic severity. OGTT analysis demonstrated comparable glucose levels but markedly elevated insulin responses across all time points in the metformin group, consistent with a compensatory hyperinsulinemic state. Both groups showed significant improvement in anthropometric and metabolic parameters at 6 months; however, partial deterioration was observed at 12 months. In adjusted analyses, metformin use remained associated with higher fasting insulin and HOMA-IR at 6 months (p < 0.01), but not at 12 months.Sex-stratified analysis revealed a more pronounced metabolic response in females.

Conclusion: Metformin-treated adolescents represent a more severe metabolic phenotype rather than a distinct therapeutic trajectory. Although early (6-month) improvements are evident, these effects are not sustained at 12 months. These findings suggest that metformin use reflects baseline disease severity rather than independently modifying long-term metabolic outcomes in pediatric obesity.This finding has been associated with environmental factors, poor treatment adherence, and difficulties in maintaining lifestyle modifications.

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