Zinc homeostasis in pediatric critical illness.
OBJECTIVE
We explored the hypothesis that marked decline in plasma zinc concentrations among critically ill children is related to shifts in metallothionein expression and inflammation.


METHODS
Prospective pilot study.


METHODS
Intensive care unit of tertiary care children's hospital.


METHODS
All children (<18 yrs) with unadjusted Pediatric Risk of Mortality III score >5 or at least one organ failure admitted to the pediatric intensive care unit from March through August 2006 were eligible for enrollment.


METHODS
After consent, blood samples were collected on days 1 and 3 of illness and analyzed for serum chemistries, plasma zinc and copper levels, metallothionein isoform expression, and cytokine levels.


RESULTS
Twenty patients were enrolled, with median age of 2.9 yrs (interquartile range, 0.7-10.1). Male to female ratio was 1.2:1. All patients had low zinc levels (mean, 0.43; range, 0.26-0.66 mug/dL) on day 1 of pediatric intensive care unit admission, and remained low (mean, 0.51; range, 0.26-0.81 mug/dL) on day 3, even when corrected for hypoalbuminemia. In comparison, serum copper levels were normal. On day 1, there was a positive correlation between zinc levels and expression of MT-1A (p < 0.01), MT-1G (p = 0.02), and MT-1H (p = 0.03). Plasma zinc levels correlated inversely with C-reactive protein levels (r = -.75, p = 0.01) and interleukin-6 levels (r = -.53, p = 0.04) on day 3. On day 3, patients with two or more organ failures had significantly lower plasma zinc concentrations compared with patients with </=1 organ failure (p = 0.03).


CONCLUSIONS
Plasma zinc concentrations are low in critically ill children. Plasma zinc correlated with measures of inflammation (C-reactive protein and interleukin-6) on day 3; low plasma zinc concentrations were associated with the degree of organ failure on day 3. These data serve as the basis for a larger study of shifts in plasma zinc concentrations in critically children to potentially identify patients who might benefit from zinc supplementation.
Cvijanovich
Natalie Z
NZ
Divisions of Critical Care, Children's Hospital, University of Cincinatti College of Medicine, and Research Center Oakland, Oakland, CA, USA. ncvijanovich@mail.cho.org
King
Janet C
JC
Flori
Heidi R
HR
Gildengorin
Ginny
G
Wong
Hector R
HR
D000418:Albumins / Q000378:metabolism; D001774:Blood Chemical Analysis; D002648:Child; D002675:Child, Preschool; D003300:Copper / Q000032:analysis / Q000378:metabolism*; D016638:Critical Illness / Q000401:mortality*; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007223:Infant; D018836:Inflammation Mediators / Q000097:blood*; D015278:Intensive Care Units, Pediatric; D015850:Interleukin-6 / Q000097:blood / Q000378:metabolism; D016014:Linear Models; D008297:Male; D008668:Metallothionein / Q000097:blood / Q000378:metabolism; D009102:Multiple Organ Failure / Q000097:blood / Q000401:mortality; D010865:Pilot Projects; D011336:Probability; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate; D015032:Zinc / Q000097:blood / Q000378:metabolism*
D000418:Albumins; D018836:Inflammation Mediators; D015850:Interleukin-6; D003300:Copper; D008668:Metallothionein; D015032:Zinc