Background
Calprotectin (CP) is a protein complex involved in many inflammatory diseases. Obesity is characterized by low-grade inflammation and elevated circulating levels of calprotectin. However, associations between body mass index (BMI) and calprotectin levels have not been explored in otherwise healthy children.
Conclusion
Calprotectin blood levels correlate with the degree of adiposity in healthy children, but are not affected by age, sex, or sample type (serum or plasma).
Methods
In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched PubMed and Cochrane Library database up to July 2019. Healthy children's blood calprotectin values were extracted, and potential correlations were explored.
Results
A total of six studies that included data on 593 healthy children were identified. Median calprotectin value was 900.0 (482.0; 1700) ng·mL-1. Multivariable analysis showed no significant associations with age, sample type (serum vs. plasma), or sex. In contrast, a significant effect of BMI z-score (p < 0.001) emerged. Indeed, a positive correlation between BMI z-score and CP, was detected in girls (R: 0.48; p < 0.001) and boys (R: 0.39; p < 0.001).