Associations between serum C-reactive protein and serum zinc, ferritin, and copper in Guatemalan school children

Biol Trace Elem Res. 2012 Aug;148(2):154-60. doi: 10.1007/s12011-012-9358-0. Epub 2012 Feb 22.

Abstract

Inflammation affects trace nutrient concentrations, but research on copper and particularly in children is limited. We assessed associations between serum C-reactive protein (CRP) and zinc, iron, copper, and other biomarkers (alkaline phosphatase, hemoglobin, and albumin), in 634 healthy 6- to 11-year-old Guatemalan schoolchildren. CRP was measured by a standardized, high-sensitive method. For significant associations with CRP, we stratified nutrient concentrations across categories of CRP and compared concentrations above and below several CRP cutoff points (0.5, 1, 3, 5, and 10 mg/L), and then adjusted values using correction factors (ratios of geometric means of the nutrients in the low and high groups). Prevalence of serum zinc (<65 μg/dL0, ferritin (<15 μg/L), and copper (<90 μg/dL) deficiency were 21%, 2.1%, and 23.8%, respectively. Median (25th and 75th percentiles) CRP was 0.56 (0.26 and 1.54) mg/L. CRP concentration was positively associated with ferritin and copper concentrations (r = 0.23 and 0.29, respectively; P < 0.0001) but not with zinc and other biomarkers (P > 0.05). Regardless of CRP cutoffs, high (> cutoff) vs. low (≤ cutoff) CRP levels had higher ferritin and copper concentrations and lower prevalence of copper deficiency of <90 μg/dL (P < 0.05). Adjustment for inflammation had the greatest influence on recalculated prevalence for the CRP 0.5 mg/L cutoff. The low ferritin prevalence hardly changed (from 2.1% to 2.5%) while the low copper prevalence changed appreciably (from 23.8% to 31.2%). In conclusion, CRP was positively associated with ferritin and copper but not with zinc concentrations. Adjustment for inflammation had little effect on low ferritin prevalence, low to begin with, and a large impact on low copper prevalence. High-sensitive CRP methods and the use of very low CRP cutoffs may be more accurate than traditional CRP methods in the adjustment of serum copper concentrations for inflammation in healthy school children.

MeSH terms

  • Alkaline Phosphatase / blood
  • C-Reactive Protein / metabolism*
  • Child
  • Copper / blood*
  • Copper / deficiency
  • Female
  • Ferritins / blood*
  • Ferritins / deficiency
  • Guatemala / epidemiology
  • Hemoglobins / analysis
  • Humans
  • Inflammation / blood
  • Inflammation / epidemiology
  • Iron / blood*
  • Iron Deficiencies
  • Male
  • Prevalence
  • Reproducibility of Results
  • Schools
  • Sensitivity and Specificity
  • Trace Elements / analysis
  • Trace Elements / deficiency
  • Zinc / blood*
  • Zinc / deficiency

Substances

  • Hemoglobins
  • Trace Elements
  • Copper
  • C-Reactive Protein
  • Ferritins
  • Iron
  • Alkaline Phosphatase
  • Zinc