Metformin for pediatric obesity and insulin resistance: a retrospective study within an integrated health care system.

OBJECTIVE

Few treatments exist for pediatric obesity. Metformin holds potential for pediatric weight loss. This large retrospective study examined the effect of metformin on weight, BMI, BMI z score, and cardiometabolic outcomes.

METHODS

The study included 7,068 patients aged 10 to 17 years with BMI at or above the 95th percentile and evidence of insulin resistance. The final cohort of 955 patients with BMI data at 0 to 24 months was categorized into three groups: metformin plus intensive lifestyle changes, intensive counseling alone, and routine counseling. In order to adjust for pubertal BMI changes, a subgroup analysis was conducted for adolescents aged 15 to 17 years.

RESULTS

At 6 and 12 months, metformin treatment produced significant reductions in weight (-3.5 kg and -5.3 kg, p < 0.0001), BMI (-1.06 kg/m² and -1.23 kg/m², p < 0.0001), and BMI z score (-0.05 and -0.07, p ≤ 0.002), which continued to decrease at 24 months (-0.05 and -0.08, p = 0.11 and 0.01), compared with control groups. Adolescents aged 15 to 17 years showed similar improvements. Systolic blood pressure and high-density lipoprotein cholesterol also improved in the metformin group.

CONCLUSIONS

Metformin with lifestyle interventions significantly reduced weight, BMI, and BMI z score in pediatric patients with obesity and insulin resistance up to 24 months, compared with intensive and routine counseling alone.