title: The effect of smoking on the serum ionized magnesium concentration is method-dependent.
abstract: OBJECTIVE
  To investigate the effect of smoking on serum ionized magnesium concentration ([Mg2+]) determined by the NOVA and AVL Mg ion-selective electrodes (Mg ISEs).
  
  
  METHODS
  Subjects were apparently healthy smokers (n = 30) and nonsmokers (n = 30). We determined NOVA and AVL [Mg2+] in their serum and in test solutions containing compounds increased by smoking. We also determined subjects' white blood cell and differential counts.
  
  
  RESULTS
  For smokers, the mean values for NOVA and AVL [Mg2+] differed significantly (0.41 vs 0.52 mmol/L, respectively). We found a significant intramethod difference in NOVA [Mg2+] (0.11 mmol/L, P < .0001) between smokers and nonsmokers. A dose-dependent decrease in NOVA [Mg2+] was observed with an increase in cigarettes/day. NOVA [Mg2+] inversely correlated with white blood cell counts. There was no interference by the test compounds with either Mg ISE.
  
  
  CONCLUSIONS
  Smoking may induce a serum factor, possibly related to white blood cells, that negatively interferes with the response of the NOVA Mg ISE.
authors.affiliation: Clinical Pathology Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Md. 20892-1508, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Niemela
authors.forename: S A
authors.initials: SA
authors.lastname: Cecco
authors.forename: N N
authors.initials: NN
authors.lastname: Rehak
authors.forename: R J
authors.initials: RJ
authors.lastname: Elin
mesh_terms: D016718:Arachidonic Acid / Q000032:analysis; D002118:Calcium / Q000032:analysis / Q000097:blood; D003367:Cotinine / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D017736:Ion-Selective Electrodes; D007958:Leukocyte Count; D008274:Magnesium / Q000032:analysis* / Q000097:blood*; D013677:Medical Laboratory Science / Q000295:instrumentation / Q000592:standards; D009538:Nicotine / Q000032:analysis; D015203:Reproducibility of Results; D012907:Smoking / Q000009:adverse effects / Q000097:blood*
chemical_list: D016718:Arachidonic Acid; D009538:Nicotine; D008274:Magnesium; D003367:Cotinine; D002118:Calcium