Does metformin reduce obesity indices in children and adolescents?

Takeaway

• In children and adolescents, metformin use was associated with a significant reduction in body mass index (BMI), body weight, waist circumference (WC), and fat mass.
• Metformin did not show any significant effect on lean body mass (LBM).

Why this matters

• Limited data are available regarding the effects of metformin therapy on obesity indices.

Study design

• Meta-analysis included 38 studies (n=2199) after a search across SCOPUS, Medline, and Google Scholar databases.
• Funding: None.

Key results

• Metformin vs control group had significant reduction in
  • BMI (weighted mean difference [WMD], -1.07 kg/m2; 95% CI, -1.43 to -0.72; I², 98.8%);
  • WC (WMD, -1.93 cm; 95% CI, -2.69 to -1.16; I², 91.4%); and
  • body weight (WMD, -2.51 kg; 95% CI, -3.14 to -1.89; I², 96.6%).
• Metformin significantly reduced body fat mass in patients with overweight or obesity (WMD, -1.90%; 95% CI, -3.25 to -0.56) and chronic diseases (WMD, -1.41%; 95% CI, -2.23 to -0.58), but not among those with growth problems (WMD, -2.68%; 95% CI, -5.50 to -0.13).
• Metformin therapy did not affect lean body mass (LBM) in patients with overweight or obesity (WMD, -0.74kg; 95% CI, -2.40 to 0.91) and growth problems (WMD, 0.69kg; 95% CI, -1.71 to 3.09)
• Metformin use was associated with reduction in LBM in patients with chronic diseases (WMD, -1.49 kg; 95% CI, -2.69 to -0.30).

Limitations

• Heterogeneity among studies.
• Risk of bias.