Visfatin in obese children and adolescents and its association with insulin resistance and metabolic syndrome

Background: Visfatin, also known as nicotinamide phosphoribosyltransferase, is an adipokine that has been implicated in obesity, insulin resistance (IR) and diabetes mellitus. Since obesity profoundly affects serum lipids, insulin, and glucose metabolism, the aim of this study was to evaluate the relationships between visfatin and metabolic parameters in childhood obesity. Methods: A total of 73 Iranian children and adolescents (31 controls; 42 obese), between the ages of 7 and 16 years, were selected and clinically evaluated. Serum visfatin, leptin, insulin and adiponectin were measured using ELISA, and insulin resistance was calculated by the Homeostasis Model of Assessment of Insulin Resistance (HOMA-IR). Fasting plasma glucose (FPG), triglyceride (TG), total cholesterol (TC), LDL-C and HDL-C were also measured. Metabolic syndrome (MetS) was determined according to IDF criteria. Results: Obese subjects presented significantly higher levels of insulin, LDL-C, HOMA-IR, and leptin and lower levels of adiponectin. Serum Visfatin was higher in obese children than in the control children, and it was significantly higher in obese children with MetS or IR, compared with obese children without MetS or IR. Visfatin levels showed positive correlations with FPG, insulin, and HOMA-IR, in obese subjects and a negative correlation with adiponectin, but no correlation with leptin. Adiponectin levels were correlated with HDL-C and Insulin levels in obese subjects. Leptin levels were correlated with Body mass index (BMI) but not with metabolic parameters. Conclusions: Visfatin is increased in obese children and adolescents, and has a more prominent association with IR and MetS parameters, compared with leptin and adiponectin.