title: Magnesium and calcium in exhaled breath condensate of children with asthma and gastroesophageal reflux disease.
abstract: BACKGROUND
  Magnesium and calcium physiologic functions are closely related. Magnesium is primarily an intracellular cation, the action of which also involves maintenance of cellular ionic balance, while influencing calcium homeostasis by blocking calcium channels. The aim of this study was to compare the concentrations of magnesium and calcium in exhaled breath condensate (EBC) of children with asthma and gastroesophageal reflux disease (GERD).
  
  
  METHODS
  EBC was collected from 66 children aged 7-14 years (23 children with acute asthma, 17 children with GERD, and 26 healthy children). Determination of magnesium and calcium concentrations was preceded by optimization and validation for low concentrations.
  
  
  RESULTS
  No difference was recorded for either magnesium or calcium concentration between study groups. However, the magnesium to calcium ratio was statistically significantly lower in both GERD and asthma children as compared with control group.
  
  
  CONCLUSIONS
  Study results showed the magnesium to calcium ratio to be a statistically significantly better indicator of certain pathologic changes than absolute concentration of either ion.
authors.affiliation: Srebrnjak Children's Hospital, Reference Center for Clinical Pediatric Allergologyof the Ministry of Health and Social Welfare, Zagreb, Croatia. slavica.dodig@zg.t-com.hr
authors.forename: Slavica
authors.initials: S
authors.lastname: Dodig
authors.forename: Zeljka
authors.initials: Z
authors.lastname: Vlasić
authors.forename: Ivana
authors.initials: I
authors.lastname: Cepelak
authors.forename: Renata
authors.initials: R
authors.lastname: Zrinski Topić
authors.forename: Mirjana
authors.initials: M
authors.lastname: Turkalj
authors.forename: Boro
authors.initials: B
authors.lastname: Nogalo
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods*; D002118:Calcium / Q000032:analysis*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D005260:Female; D005764:Gastroesophageal Reflux / Q000378:metabolism*; D006801:Humans; D008274:Magnesium / Q000032:analysis*; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D008274:Magnesium; D002118:Calcium