Pediatric reference intervals for serum copper and zinc

BackgroundCopper and zinc are essential trace elements and nutrients, which have important roles in physiology and disease and as cofactors in many metabolic pathways. We established age- and gender-specific reference intervals for serum copper and zinc, with a large healthy pediatric population.MethodsA total of 2115 clinically healthy children, 85.4% Caucasian, were enrolled: 1098 boys and 1017 girls 0.5–18 y. Serum copper and zinc concentrations were measured by inductively coupled plasma-mass spectrometry (analytical measurement range: 10–400 μg/dl for each). Statistical analyses and related calculations were performed using the STATA Statistical software and R software.ResultsThere were no significant effects of gender or fasting status. For copper, but not zinc, there were significant differences in the reference intervals by age. Based on the central 95% and 95% confidence intervals, the resulting reference interval determined for serum zinc was 64–124 μg/dl. The age-dependent reference intervals for serum copper were 75–153 μg/dl for those < 10.3 y, 64–132 μg/dl for those 10.3–12.5 y and 57–129 μg/dl for those > 12.5 y.ConclusionsOur data defined reference intervals for serum copper and zinc in an American, clinically healthy, pediatric population.

► Pediatric reference intervals for serum copper and zinc were established with 2115 clinically healthy children.
► There were no significant effects of gender on serum copper and zinc.
► There were significant differences in the reference intervals by age, for copper, but not zinc.