Plasma visfatin concentrations are related to metabolic parameters in physically active adolescent boys

The purpose of the present study was to investigate the association of fasting plasma visfatin concentration with insulin resistance parameters according to sex in physically active adoloscent children. Thirty four healthy children (17 boys and 17 girls) aged between 13 and 16 years participated in the study. All children were swimmers recruited from local training groups and trainded for at least eight hours per week during at least last two years. The distribution of age and body mass index (BMI) was not different between boys and girls. Plasma visfatin concentrations were not different between sexes (boys: 1,3+- 0,0 ng/ml;girls 1.2 ng/ml). No differences were also observed for insulin, glucose and fasting insulin resistance index (FIRI) values between studied groups, while girls presented significantly higher values for leptin compared to boys. Plasma visfatin concentrations were realted to the markers of insulin sensitivity (insulin , FIRI) and BMI only in boys, while no relationship between these parameters was observed in girls. In conclusion, the results of this study suggested that plasma visfatin concentrations are not different between regularly physically active boys and girls. In addition, our findings indicated that the associations of fasting plasma visfatin concentrations with metabolic and body composition paraemters were sex-dependent in children