Introduction: Early childhood obesity may play an important role in development of the metabolic syndrome characterized by abnormalities in several major cardiovascular risk factors. Only a few studies demonstrate that weight reduction leads to an improvement of the atherogenic risk-factor profile in prepubertal children.

Aim: The aim of this study was to assess the concentration of C-peptide and selected parameters of lipid profile in prepubertal obese children before and after weight reduction therapy.

Material and methods: Changes in nutrition, anthropometric and biochemical parameters including C-peptide concentration and lipid profile were determined in 52 obese children (z-score BMI≥2SD) aged 4-10 years, before and after a 3-months lifestyle intervention programme. This programme consisted of dietary (1200-1400 kcal/day) and physical activity modifications and behaviour therapy, including individual psychological care of the child and its family. The reference group consisted of 30 healthy normal-weight children. Total cholesterol, LDL and HDL-cholesterol and triglicerydes levels were measured by routine enzymatic methods. Concentration of C-peptide was determined using the immunoenzymatic kit.

Results: All obese children were divided into two groups: A and B. In group A with decreased BMI by 10% (25.4±3.1 vs 22.8±2.9 kg/m2; p<0.01) after the 3-months therapy we found also decreased concentrations of triglicerydes and C-peptide by about 20% (77.9±28.5 vs 60.7±17.5 mg/dl; p<0.02) and 35% (2.96±1.52 vs 1.94±1.40 ng/ml; p<0.05) respectively. In group B, without changes in the BMI during therapy, no significant differences in these biochemical parameters were observed. Moreover, higher level of total cholesterol and LDL-cholesterol by 10% (p<0.05) observed in this group may be related to dietary cholesterol, which was similar both at baseline and 3 months later.

Conclusion: We suggest that weight-reduction programme is necessary in prepubertal obese children with abnormal lipid profile as a prevention of metabolic syndrome in later life. Our findings support the beneficial effects of weight reduction programme if it is accepted by obese children and their parents. Additionally, we suggest, that C-peptide may be useful in monitoring of this therapy. Further studies with longer term intervention are needed to confirm the value of this biochemical marker in the management of prepubertal obese children.