title: Hyperhomocysteinemia measured by immunoassay: a valid measure of coronary artery atherosclerosis.
abstract: BACKGROUND
  Homocysteine is emerging as a novel marker of atherothrombosis. Its role as an independent risk factor for cardiovascular disease is generally accepted. There is scanty data correlating homocysteine levels measured by immunoassay with cardiovascular disease. We previously validated a fluorescence polarization immunoassay for measuring homocysteine, which compared favorably with high performance liquid chromatography.
  
  
  OBJECTIVE
  To determine if homocysteine levels measured by immunoassay correlate with extent of atherosclerotic burden, as represented by degree of coronary artery stenosis determined by coronary angiography.
  
  
  METHODS
  Fasting plasma samples were obtained from patients undergoing coronary angiography (N = 165). Homocysteine levels were measured by immunoassay and coronary artery stenosis was determined by coronary angiography.
  
  
  RESULTS
  Median coronary artery stenosis for the 3 homocysteine subgroups, less than 1.35, 1.35 to 6.75, and greater than 6.75 mg/L (<10, 10-15, and >15 micromol/L), was 75%, 90%, and 99%, respectively (P = .01 for trend). Also, folate and vitamin B12 levels decreased with increasing homocysteine levels (P = .01 and .04, respectively, for trend). Spearman's correlation showed a significant association between homocysteine level and coronary artery stenosis (r = 0.20; P = .009). When men and women were examined separately, the correlation was significant only for women (r = 0.30; P = .01).
  
  
  CONCLUSIONS
  Homocysteine levels, as measured by immunoassay, show a positive correlation with cardiovascular disease in women. Thus, this is a valid measure of atherosclerotic burden and, therefore, a reliable addition to the established laboratory repertoire for the assessment of cardiovascular disease.
authors.affiliation: Department of Pathology, The University of Texas Southwestern Medical Center at Dallas, USA.
authors.forename: Michele T
authors.initials: MT
authors.lastname: Stauffenberg
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lange
authors.forename: L David
authors.initials: LD
authors.lastname: Hillis
authors.forename: Joaquin
authors.initials: J
authors.lastname: Cigarroa
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Hsu
authors.forename: Sridevi
authors.initials: S
authors.lastname: Devaraj
authors.forename: Ishwarlal
authors.initials: I
authors.lastname: Jialal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography / Q000592:standards; D003324:Coronary Artery Disease / Q000097:blood* / Q000175:diagnosis; D023921:Coronary Stenosis / Q000097:blood / Q000473:pathology; D005215:Fasting / Q000097:blood; D005260:Female; D016231:Fluorescence Polarization Immunoassay / Q000592:standards*; D006711:Homocystine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged
chemical_list: D006711:Homocystine