Low plasma vitamin B-6 concentrations and modulation of coronary artery disease risk

Am J Clin Nutr. 2004 Jun;79(6):992-8. doi: 10.1093/ajcn/79.6.992.


Background: Low concentrations of pyridoxal-5'-phosphate (PLP), the active metabolite of vitamin B-6, are associated with high C-reactive protein (CRP) concentrations. Both low PLP and elevated inflammatory markers, such as high-sensitivity CRP (hs-CRP) and fibrinogen, are related to higher risk of coronary artery disease (CAD).

Objectives: The objectives were to evaluate the relation between PLP and acute-phase reactants in affecting CAD risk and to estimate the risk of CAD related to low plasma PLP, either alone or in combination with high concentrations of acute-phase reactants and other classic risk factors for CAD.

Design: A case-control study was conducted with 742 participants: 475 with severe multivessel CAD and 267 free from coronary atherosclerosis (CAD-free). We measured plasma PLP, fibrinogen, hs-CRP, and serum lipid concentrations and all major biochemical CAD risk factors, including total homocysteine.

Results: A significant, inverse, graded relation was observed between PLP and both hs-CRP and fibrinogen (P < 0.001). The prevalence of PLP concentrations in the lower half of the population (<50th percentile: 36.3 nmol/L) was significantly higher among CAD patients than among CAD-free subjects (P < 0.001). The odds ratio for CAD risk related to low PLP concentrations after adjustments for the major classic CAD risk factors, including hs-CRP and fibrinogen, was 1.89 (95% CI: 1.18, 3.03; P = 0.008). The CAD risk as a result of low PLP was additive when considered in combination with elevated hs-CRP concentrations or with an increased ratio of LDL to HDL.

Conclusion: Low plasma PLP concentrations are inversely related to major markers of inflammation and independently associated with increased CAD risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Proteins / metabolism*
  • C-Reactive Protein / metabolism*
  • Case-Control Studies
  • Cholesterol / blood
  • Coronary Artery Disease / blood*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pyridoxal Phosphate / blood*
  • Risk Factors
  • Vitamin B 6 Deficiency / blood*


  • Acute-Phase Proteins
  • Pyridoxal Phosphate
  • C-Reactive Protein
  • Cholesterol