title: Niacin treatment increases plasma homocyst(e)ine levels.
abstract: BACKGROUND
  Studies have reported high levels of plasma homocyst(e)ine as an independent risk factor for arterial occlusive disease. The Cholesterol Lowering Atherosclerosis Study reported an increase in plasma homocyst(e)ine levels in patients receiving both colestipol and niacin compared with placebo. Thus the objective of this study was to examine the effect of niacin treatment on plasma homocyst(e)ine levels.
  
  
  METHODS
  The Arterial Disease Multiple Intervention Trial, a multicenter randomized, placebo-controlled trial, examined the effect of niacin compared with placebo on homocyst(e)ine in a subset of 52 participants with peripheral arterial disease.
  
  
  RESULTS
  During the screening phase, titration of niacin dose from 100 mg to 1000 mg daily resulted in a 17% increase in mean plasma homocyst(e)ine level from 13.1 +/- 4.4 micromol/L to 15.3 +/- 5.6 micromol/L (P <.0001). At 18 weeks after randomization, there was an absolute 55% increase from baseline in mean plasma homocyst(e)ine levels in the niacin group and a 7% decrease in the placebo group (P =.0001). This difference remained statistically significant at the end of follow-up at 48 weeks.
  
  
  CONCLUSIONS
  Niacin substantially increased plasma homocyst(e)ine levels, which could potentially reduce the expected benefits of niacin associated with lipoprotein modification. However, plasma homocyst(e)ine levels can be decreased by folic acid supplementation. Thus further studies are needed to determine whether B vitamin supplementation to patients undergoing long-term niacin treatment would be beneficial.
authors.affiliation: Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA. garg_rehka@lilly.com
authors.forename: R
authors.initials: R
authors.lastname: Garg
authors.forename: M
authors.initials: M
authors.lastname: Malinow
authors.forename: M
authors.initials: M
authors.lastname: Pettinger
authors.forename: B
authors.initials: B
authors.lastname: Upson
authors.forename: D
authors.initials: D
authors.lastname: Hunninghake
mesh_terms: D000368:Aged; D005260:Female; D006711:Homocystine / Q000097:blood* / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009525:Niacin / Q000494:pharmacology*
chemical_list: D009525:Niacin; D006711:Homocystine