Circulating resistin concentrations in children depend on renal function.

BACKGROUND Resistin is a newly discovered peptide hormone that inhibits adipogenesis. Furthermore, it may be involved in regulative processes taking place in insulin resistance and inflammation. In human beings as well as in rodents, the exact physiological role of resistin is unknown. The objective of this study was to examine whether resistin serum concentrations in childhood are regulated by renal function. METHODS Fifteen patients with end stage renal disease treated by haemodialysis (HD) (6m, 9f; age (median (25-75% percentile)) 16.1 (14.2-16.9) years; body mass index (BMI) 17.8 (17.6-20.6) kg/m2; glomerular filtration rate (GFR)<10 ml/min/1.73 m2), 11 patients with chronic renal failure (CRF) (4m, 7f; age 11.3 (9.2-16.9) years; BMI 17.9 (15.4-22.1) kg/m2; GFR 21.2 (19.8-39.4) ml/min/1.73 m2) and 23 healthy children (13m, 10f; age 7.8 (4.7-14.5) years; BMI 16.5 (14.9-18.1) kg/m2; GFR 168.5 (154.0-197.2) ml/min/1.73 m2) were included. Resistin concentration in serum was measured by ELISA, leptin by RIA. RESULTS Resistin concentrations were significantly elevated in HD (6.6 (5.7-8.7) ng/ml) and CRF (4.8 (4.1-6.2) ng/ml) compared to healthy controls [2.7 (2.0-3.6) ng/ml; P<0.0001 by multiple regression analysis]. Furthermore, resistin concentrations showed a tendency to be higher in children below the age of 5.5 years (youngest tertile) and above 12.5 years of age (oldest tertile), compared to children aged between 5.5 and 12.5 years (P=0.053 and P=0.043, respectively). Gender (P=0.686) and BMI (P =0.663) did not have a significant influence on resistin concentrations. Resistin and leptin serum concentrations correlated in HD patients only (r=0.62, P=0.013 by Spearman correlation). Haemodialysis did not eliminate resistin. CONCLUSIONS With decreasing renal function, resistin concentration in serum increases in our small paediatric cohort. Age possibly influences circulating resistin concentration. The hypothesis that elevated serum resistin in children with chronic renal failure or end stage renal disease may add to malnutrition and reduced BMI needs further investigation and is not supported by our data.