Introduction

Childhood obesity is a growing global health concern, strongly associated with chronic low-grade inflammation and increased risk of metabolic, cardiovascular, and renal complications. Identifying early biomarkers of obesity-related disorders is essential for timely intervention and prevention. This study aimed to evaluate selected serum and urinary biomarkers in children and adolescents aged 8–18 years to assess their relationship with overweight and obesity and their potential as early indicators of metabolic disturbances.

Material and methods

A total of 268 participants were included: 200 children with excessive body weight (body mass index – BMI ≥ 85th percentile) and 68 children with normal weight (BMI < 85th percentile), classified according to the Polish OLAF percentile charts. Biochemical markers analysed in serum included high-density lipoprotein (HDL)-C, low-density lipoprotein (LDL)-C, creatinine (Cr), uric acid, isthmin-1, visfatin, resistin, and in urine, α-1-acid glycoprotein (α1AGP)/Cr.

Results

The study group had significantly lower HDL-C concentrations compared to their normal-weight peers. No statistically significant differences were observed in LDL-C or serum Cr levels between the groups. However, the study group exhibited significantly higher serum resistin levels and an elevated urine α1AGP/Cr. In contrast, concentrations of serum isthmin-1 and visfatin were significantly lower in the study group than in the control group. Correlation analysis using Spearman’s test showed no significant associations between concentrations of adipokines and uric acid.

Conclusions

This study demonstrated significant differences in biochemical and inflammatory markers between children with overweight/obesity and their normal-weight peers, including decreased HDL-C and visfatin, lower isthmin-1, and elevated resistin and α1AGP/Cr. These findings may reflect early metabolic and inflammatory disturbances that occur even before clinical symptoms arise. The lack of correlation between adipokines and uric acid suggests distinct, independent mechanisms involved in obesity-related complications. Monitoring these biomarkers may support early detection and prevention strategies in paediatric populations at risk of metabolic disorders.