A 24-month metformin treatment study of children with obesity: Changes in circulating GDF-15 and associations with changes in body weight and visceral fat.

Background Metformin treatment for 24 months in children with obesity lowers body mass index (BMI), reduces liver fat, and normalizes endocrine-metabolic parameters. Objective Here we study whether circulating GDF-15 levels were raised by such metformin treatment and whether they related to changes in body weight and visceral fat in children with obesity. Methods The study population consisted of 18 pre-pubertal/early pubertal children with obesity who had participated in a randomized double-blind clinical trial receiving metformin (850 mg/day) or placebo for 24 months. Circulating GDF-15, BMI and abdominal visceral and liver fat (magnetic resonance imaging) were assessed at 0, 6, 12 and 24 months. Results Results showed that metformin-treated children had higher GDF-15 levels at 6 and 12 months. Higher rises of circulating GDF-15 associated with more loss of body weight and visceral fat. Conclusion In conclusion, the concept that GDF-15 is among the mediators of metformin's normalizing effects in individuals with obesity is herewith extended into childhood.