Effects of metformin on anthropometric indices and hormones and adipocytokine concentrations in children with overweight or obesity: a systematic review and meta-analysis of randomised controlled trials

Clinical Snapshot

Key Findings

• P Value: Not reported in abstract

• Effect Size: BMI: MD -1.07 kg/m²; BMI-Z score: MD -0.09; Body weight: MD -3.20 kg

• Primary Outcome: BMI reduction of 1.07 kg/m² favouring metformin

• Nnt Or Sensitivity: Clinically meaningful BMI reduction of >1 kg/m² achieved

• Confidence Interval: BMI: 95% CI -1.62 to -0.52; BMI-Z: 95% CI -0.13 to -0.05; Weight: 95% CI -4.21 to -2.19

Clinical Application

Metformin is widely available, well-tolerated in paediatric populations, and cost-effective Metformin is PBS-listed for type 2 diabetes; off-label use for paediatric obesity would require specialist consideration and family discussion about evidence limitations Children and adolescents with overweight or obesity, particularly those with insulin resistance

Abstract

OBJECTIVE: The aim of this systematic review was to assess the effect of metformin on anthropometric indices, hormones and adipocytokine concentrations in children with overweight or obesity. METHODS: Eligible studies were searched via PubMed, Scopus, Cochrane Central Register of Controlled Trials, alongside clinical trial registries and the reference lists of included studies, from inception to October 2024. Screening was carried out independently by two reviewers, involving title-abstract screening for relevance, followed by full-text review for eligibility confirmation. Data extraction was performed by two independent investigators using an identical Excel spreadsheet. A meta-analysis was conducted using the random-effects model. RESULTS: A total of 19 original studies were deemed eligible for this systematic review. Metformin was more effective than placebo in improving Body Mass Index (BMI), BMI-Z score, body weight, fasting insulin and leptin concentrations (mean difference (MD) -1.07 kg/m2, 95% CI -1.62 to -0.52; MD -0.09, 95% CI -0.13 to -0.05; MD -3.20 kg, 95% CI -4.21 to -2.19; MD -3.38 μU/mL, 95% CI -6.00 to -0.75; MD -3.73 ng/mL, 95% CI -6.28 to -1.18, respectively). There was no difference between metformin and placebo on adiponectin and resistin concentrations, as well as adiponectin to leptin ratio. CONCLUSION: Metformin may have a role as an adjuvant therapy in managing overweight and obesity among the paediatric population. Regarding the concentrations of adipokines and hormones, the results are inconclusive. More randomised controlled trials with rigorous methodology and homogeneity in population and intervention characteristics are needed to shed light on this topic. TRIAL REGISTRATION NUMBER: PROSPERO CRD42023401732.

References

1. 1.Theodoridis, X., Papaemmanouil, A., Papageorgiou, N., Chrysoula, L., Stabouli, S., & Chourdakis, M. (2026). Effects of metformin on anthropometric indices and hormones and adipocytokine concentrations in children with overweight or obesity: a systematic review and meta-analysis of randomised controlled trials. Archives of Disease in Childhood. https://doi.org/10.1136/archdischild-2025-328782