ESPE Abstracts

Background/Aim: Serum NAMPT (nicotinamide phosphoribosyltransferase) levels are altered in adult patients with non-alcoholic fatty liver disease (NAFLD). However, less is known about NAMPT serum levels children and adolescents and their association with parameters of liver function.

Methods: Blood and anthropometric data of 416 children and adolescents who participated in the LIFE Child Study Leipzig were collected. Serum NAMPT (Adipogen) and cytokeratin-18 (PEVIVA^®, TECOmedical) levels were measured by ELISA Kit. Vibration-Controlled Transient Elastography (VCTE) and Controlled Attenuation Parameter (CAP) (FibroScan^®, M Probe, 10 successful measurements) were used to define the liver fibrosis and steatosis, respectively. Association between NAMPT serum levels with liver parameters (alanine aminotransferase (ALAT), γ-glutamyltransferase (GGT), aspartate aminotransferase (ASAT), VCTE, CAP, cytokeratin-18 (CK18), pediatric NAFLD score) as well as metabolic and inflammatory markers were calculated by Spearman’s correlation or multiple regression analysis. Differences between groups were calculated by Mann–Whitney U test.

Results: We found no differences in serum NAMPT levels between girls and boys. A positive correlation of NAMPT with anthropometric data such as BMI [kg/m²] (r=0.141, P=0.005) and hip circumference [cm] (r=0.132, P=0.01) was detected in all children and adolescents. Alanine aminotransferase level (ALAT) [U/l] were positively correlated with serum NAMPT, especially in children with obesity (r=0.211, P=0.02). In this subgroup, γ-glutamyltransferase (GGT) [U/l] (r=0.333, P=0.021) and CK18 (r=0.205, P=0.015) showed a positive correlation with NAMPT in serum However, no correlation could be found with liver steatosis and fibrosis as measured by FibroScan^® as well as the calculated pediatric NAFLD score. Further, circulating NAMPT was correlated with inflammatory markers such as C-reactive protein [mg/l] (r=0.252, P=0.000), leucocyte count [10⁹/l] (r=0.350, P=0.000) and neutrophil count [10⁹/l] (r=0.298, P=0.000), in particular in children with overweight (C-reactive protein: r=0.361, P=0.014; leucocyte count: r=0.467, P=0.007; neutrophil count: r=0.375, P=0.007) and obesity (C-reactive protein: r=0.326, P=0.000, leucocyte count: r=0.336, P=0.000). After multiple regression analysis and adjustment on BMI-SDS, age and sex, association between NAMPT and inflammatory markers but not liver parameters remained, especially leucocyte count, in all children and adolescents (R²=0.126, P=0.000) as well as in children and adolescents with overweight (R² =0.289, P=0.002).

Discussion: Our data show that serum NAMPT levels in children and adolescents are not associated parameters of liver dysfunction. We could confirm previous studies that showed a positive association with NAMPT serum levels and inflammatory markers in children and adolescents.