title: Determinants and distributions of plasma total homocysteine concentrations among school children in Taiwan.
abstract: BACKGROUND
  Plasma total homocysteine (tHcy) level is an independent risk factor for cardiovascular disease (CVD) even among children. The purpose of this study is to evaluate the determinants and distributions of plasma tHcy levels and the relationship between plasma tHcy, folate and vitamin B12 levels among school children in Taipei.
  
  
  METHODS
  After multi-stage sampling, we randomly selected 1234 school children (609 boys and 625 girls) with the mean age of 13 years (from 12 to 15 years) in this study. Fasting plasma tHcy levels were measured using an ABBOTT IMx analyzer (Axis Biochemicals ASA, Oslo, Norway). Plasma folate and vitamin B12 levels were measured by ACS:180 automated chemiluminescence analyzer (Bayer, Tarrytown, NY, USA).
  
  
  RESULTS
  The distribution of plasma tHcy levels were skewed to the right with the mean values of 10.50 and 8.95 micromol/l and medians of 9.67 and 8.474 micromol/l for boys and girls, respectively. Plasma tHcy concentrations were lower in younger children and progressively increased with increasing age. Boys had significantly higher plasma tHcy levels than girls (10.50 +/- 4.134 vs. 8.95 +/- 2.61 micromol/l, p < 0.01) and lower plasma folate levels (6.05 +/- 2.85 vs. 6.39 +/- 2.58 nmol/l, p < 0.01), and vitamin B12 levels (444.8 +/- 158.4 vs. 495.0 +/- 181.5 pmol/l, p < 0.001). Plasma tHcy levels were significantly positively associated with anthropometric measures in boys; but these characteristics attenuated and became insignificant after adjusting for other potential confounders in girls. Plasma tHcy levels were negatively associated with plasma folate and vitamin B12 levels even after adjusting for BMI and other potential confounders in both genders.
  
  
  CONCLUSIONS
  From this study, the distributions of tHcy levels were skewed to the right and the boys had higher plasma tHcy levels than girls. Plasma tHcy levels were significantly positively associated with BMI among boys. Further studies are needed to evaluate the relationship between tHcy and CVD risk factors among children for the better prevention of heart disease in early life.
authors.affiliation: Division of Clinical Pathology, Department of Pathology Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
authors.forename: J B
authors.initials: JB
authors.lastname: Chang
authors.forename: N F
authors.initials: NF
authors.lastname: Chu
authors.forename: M H
authors.initials: MH
authors.lastname: Shen
authors.forename: D M
authors.initials: DM
authors.lastname: Wu
authors.forename: Y H
authors.initials: YH
authors.lastname: Liang
authors.forename: S M
authors.initials: SM
authors.lastname: Shieh
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000886:Anthropometry; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005494:Folic Acid Deficiency / Q000150:complications; D006306:Health Surveys; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D008297:Male; D012307:Risk Factors; D012574:Schools; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology; D014805:Vitamin B 12 / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000150:complications
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12