title: Questionable Reliability of Homocysteine as the Metabolic Marker for Folate and Vitamin B12 Deficiency in Patients with Chronic Obstructive Pulmonary Disease.
abstract: BACKGROUND
  An increased homocysteine (Hcy) concentration may represent a metabolic marker of folate and vitamin B12deficiency, both significant public health problems. For different reasons, patients with chronic obstructive pulmonary disease (COPD) are prone to these deficiencies. The study evaluates the reliability of Hcy concentration in predicting folate or vitamin B12deficiency in these patients.
  
  
  METHODS
  A group of 50 COPD patients (28 males/22 females, age (χ̄±SD=49.0±14.5) years was enrolled. A chemiluminescent microparticle immunoassay was applied for homocysteine, folate and vitamin B12concentration. Kolmogorov-Smirnov, Mann-Whitney U and χ2tests, Spearman's correlation and ROC analysis were included in the statistical analysis, with the level of significance set at 0.05.
  
  
  RESULTS
  Average (SD) concentrations of folate and vitamin B12were 4.13 (2.16) μg/L and 463.6 (271.0) ng/L, whereas only vitamin B12correlated with the Hcy level (P=-0.310 (R=0.029)). Gender related differences were not significant and only a borderline significant correlation between age and folate was confirmed (R=0.279 (P=0.047)). The incidence of folate and vitamin B12 deficiency differed significantly (P=0.000 and P<0.000 for folate and vitamin B12respectively), depending on the cutoff used for classification (4.4, 6.6 and 8.0 μg/L - folate; 203 and 473 ng/L - vitamin B12). ROC analyses failed to show any significance of hyperhomocysteinemia as a predictor of folate or vitamin B12deficiency.
  
  
  CONCLUSIONS
  Reliability of the Hcy concentration as a biomarker of folate or vitamin B12depletion in COPD patients is not satisfactory, so their deficiency cannot be predicted by the occurrence of HHcy.
authors.affiliation: Center for Medical Biochemistry, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Anđelo
authors.initials: A
authors.lastname: Beletić
authors.affiliation: Center for Medical Biochemistry, Clinical Center of Serbia, Belgrade, Serbia; Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia.
authors.forename: Duško
authors.initials: D
authors.lastname: Mirković
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia; Clinic for Lung Diseases, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Dudvarski-Ilić
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia; Clinic for Lung Diseases, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Branislava
authors.initials: B
authors.lastname: Milenković
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia; Clinic for Lung Diseases, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Ljudmila
authors.initials: L
authors.lastname: Nagorni-Obradović
authors.affiliation: Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia.
authors.forename: Valentina
authors.initials: V
authors.lastname: Đorđević
authors.affiliation: Center for Medical Biochemistry, Clinical Center of Serbia, Belgrade, Serbia; Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Ignjatović
authors.affiliation: Society of Medical Biochemists of Serbia, Belgrade, Serbia.
authors.forename: Nada
authors.initials: N
authors.lastname: Majkić-Singh
keywords: COPD; folate; homocysteine; vitamin B12