Background: A number of metabolic changes are caused by childhood obesity, including insulin-resistance, diabetes and dyslipidemia. To counteract them, lifestyle modification with changes in dietary habits and physical activity is the primary intervention. Anthropometric parameters may not identify all positive changes associated with lifestyle modifications, whereas circulating adipokines may represent an alternative as biomarkers. The aim of this study was to evaluate adiponectin and leptin levels as markers of positive metabolic outcomes in childhood obesity.

Methods: Changes in clinical, anthropometric and metabolic parameters, including adiponectin and leptin, were assessed in 104 overweight and obese children before and after 1 year of lifestyle intervention. Obesity and overweight were defined according to the Italian BMI reference tables for age and sex. Fifty-four normal weight children were evaluated as controls. Forty-eight (47.5%) of the children returned for follow-up at 1 year.

Results: Compared to normal weight children, overweight and obese subjects differed significantly at baseline for glycemia, insulinemia, HOMA-IR, adiponectinemia (5.8 µg/ml versus 18.2 µg/ml in controls), LDL-cholesterol, and triglycerides. These parameters were all higher in the overweight/obese children. At follow-up, most parameters improved in overweight/obese children. The most significant changes were observed in adiponectin concentration, which increased by 245% (p<0.0001), reaching the levels observed in normal weight children. Leptin levels showed changes unrelated to positive metabolic outcomes, remaining high at 1 year of follow-up in overweight/obese children. Regardless of changes in weight status, children with lifestyle intervention reported changes in HOMA-IR and in adiponectin associated with fat mass loss.

Conclusions: After lifestyle intervention, adiponectin increased regardless of changes in weight, whereas no consistent changes was observed in serum leptin. Therefore, circulating adiponectin may represent a good biomarker to evaluate the efficacy of lifestyle intervention in overweight/obese children.