title: Plasma S-adenosylhomocysteine is a more sensitive indicator of cardiovascular disease than plasma homocysteine.
abstract: BACKGROUND
  Although plasma total homocysteine has been identified as an independent risk factor for vascular disease in a multitude of studies, there is a considerable overlap in values between patients at risk and control subjects. The difference in values can be used to distinguish statistically between the 2 groups, provided each group is large enough; however, discriminating between individual patients at risk and control subjects is difficult.
  
  
  OBJECTIVE
  We investigated whether the precursor of homocysteine, S-adenosylhomocysteine, is a more sensitive indicator of risk.
  
  
  METHODS
  We measured plasma total homocysteine, S-adenosylhomocysteine, S-adenosylmethionine, creatinine, folate, and vitamin B-12 in 30 patients with proven cardiovascular disease and 29 age- and sex-matched control subjects.
  
  
  RESULTS
  The homocysteine values (+/-SD) were 12.8 +/- 4.9 (95% CI: 11.0, 14.7) micromol/L for patients and 11.0 +/- 3.2 (9.8, 12.2) micromol/L for control subjects. The S-adenosylhomocysteine values were 40.0 +/- 20.6 (32.3, 47.7) nmol/L for patients and 27.0 +/- 6.7 (24.5, 30.0) nmol/L for control subjects (P = 0.0021). The S-adenosylmethionine values were 121.8 +/- 42.9 (105.8, 137.8) nmol/L for patients and 103.9 +/- 21.8 (95.6, 112.2) nmol/L for control subjects (P = 0.0493). The creatinine values were 110 +/- 27 (97, 120) micromol/L for patients and 97 +/- 9 (80, 100) micromol/L for control subjects (P = 0.0025). Values for folate and vitamin B-12 did not differ significantly between groups.
  
  
  CONCLUSIONS
  Plasma S-adenosylhomocysteine appears to be a much more sensitive indicator of the difference between patients with cardiovascular disease and control subjects than is homocysteine. Both plasma total homocysteine and S-adenosylhomocysteine are significantly correlated with plasma creatinine in patients.
authors.affiliation: Departments of Biochemistry and Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Kerins
authors.forename: M J
authors.initials: MJ
authors.lastname: Koury
authors.forename: A
authors.initials: A
authors.lastname: Capdevila
authors.forename: S
authors.initials: S
authors.lastname: Rana
authors.forename: C
authors.initials: C
authors.lastname: Wagner
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood* / Q000209:etiology; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012435:S-Adenosylhomocysteine / Q000097:blood*; D012436:S-Adenosylmethionine / Q000097:blood; D012680:Sensitivity and Specificity; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D012436:S-Adenosylmethionine; D005492:Folic Acid; D012435:S-Adenosylhomocysteine; D003404:Creatinine; D014805:Vitamin B 12