Can stanniocalcin-2 be regarded as a novel non-invasive biomarker of advanced liver steatosis in obese children? A preliminary study

Introduction
With the increasing prevalence of liver steatosis, non-invasive methods are sought to detect it and to assess the degree of lipid accumulation in the liver. The aim of this preliminary study was to assess the serum concentrations of stanniocalcin-2 (STC-2), pregnancy-associated plasma protein A (PAPP-A) and insulin-like growth factor binding protein (IGFBP-4) among children with obesity, check if they detect liver steatosis and determine whether they differentiate mild and advanced steatosis.

Material and methods
This prospective study involved 62 obese children (39 boys and 23 girls, median age 13.75 years). Infectious, autoimmune, metabolic and toxic liver conditions were excluded. All subjects underwent body composition analysis, anthropometric measurements, abdominal ultrasound and routine blood chemistry analyses. STC-2, PAPPA and IGFBP-4 were measured using ELISA kits. The control group consisted of 19 non-obese, healthy children with correct body mass index and without organic pathologies.

Results
The concentration of examined biomarkers in obese children with liver steatosis was significantly higher than in the control group and STC-2 was also significantly higher in children with advanced steatosis in comparison to children with mild steatosis. In the group of obese children with liver steatosis STC-2 positively correlated with: gamma-glutamyltransferase, cholesterol, triglycerides, low-density lipoprotein cholesterol, homeostatic model assessment-insulin resistance and waist-hip ratio. The ability of serum STC-2 to detect advanced liver steatosis was significant (AUC = 0.746, p = 0.0022, cut-off 135.27 pg/ml).

Conclusions
This preliminary study demonstrated that STC-2 can be regarded as a potential non-invasive marker of advanced liver steatosis in obese children. The other analyzed parameters (PAPP-A and IGFBP-4) seem not to be useful in diagnosis of liver steatosis in obese children.