Serum visfatin and vaspin levels in prepubertal children: effect of obesity and weight loss after behavior modifications on their secretion and relationship with glucose metabolism

Objective: To investigate the impact of obesity, weight loss and oral glucose ingestion on serum visfatin and vaspin levels in prepubertal children. Subjects and methods: A total of 100 prepubertal obese Caucasian children (OB) and 42 controls (C) were studied. The OB group was studied at baseline and after moderate (n=46) and extensive (n=14) body mass index (BMI) reduction by conservative treatment, undergoing body composition studies (dual-energy X-ray absorptiometry) and oral glucose tolerance tests (OGTTs). Serum visfatin and vaspin levels were studied throughout the OGTT, as were their relationships with insulin, leptin, leptin soluble receptor (sOB-R), adiponectin (total and high molecular weight), resistin, interleukin-6 (IL-6) and tumor necrosis factor-alpha levels at every time point. Results: OB had higher visfatin (P<0.001), but similar vaspin than C. BMI reduction decreased visfatin levels (P<0.001), with BMI, waist circumference and the surrogate markers of body fat (leptin and sOB-R) showing significant correlations (P<0.05) with this peptide, but not with vaspin. Visfatin and vaspin decreased during the OGTT (P<0.001). Weight reduction did not alter visfatin dynamics in the OGTT, but decreased the area under the curve (AUC) for vaspin (P<0.001), with a correlation between the AUCs for vaspin and insulin after weight loss (P<0.05). Visfatin levels were positively correlated with resistin and IL-6, after controlling for BMI and HOMA (homeostatic model assessment) index at every time point in the study. Conclusion: Serum visfatin, but not vaspin, levels are influenced by body fat content in obese children, whereas both adipokines are modulated by glucose intake in a BMI-dependent manner. International Journal of Obesity (2011) 35, 1355-1362; doi: 10.1038/ijo.2010.280; published online 25 January 2011