Plasma pyridoxal-5-phosphate and future risk of myocardial infarction in the European Prospective Investigation into Cancer and Nutrition Potsdam cohort.
BACKGROUND
Retrospective studies indicate that low concentrations of plasma pyridoxal-5-phosphate (PLP) are associated with cardiovascular events; however, few prospective studies of this issue have been conducted.


OBJECTIVE
We therefore investigated whether PLP concentrations are independently associated with myocardial infarction (MI) in the European Investigation into Cancer and Nutrition (EPIC) Potsdam Study.


DESIGN
After exclusion of prevalent MI or stroke, incident cases of MI were identified among 26 761 participants (aged 35-65 y at baseline). The current analysis is based on a nested case-cohort study consisting of a control group of 810 subjects without MI or stroke at baseline and a case group of 148 subjects who had an MI during a mean follow-up period of 6.0 +/- 1.5 y. Cox proportional hazard models were used to evaluate the association between plasma PLP and risk of MI.


RESULTS
In the age- and sex-adjusted analysis, subjects in the highest quintile of PLP had a significantly reduced risk of MI (hazard ratio: 0.50; 95% CI: 0.29, 0.83). Adjustment for either low-grade inflammation or smoking diminished this association. When both low-grade inflammation and smoking were adjusted for, the association was abolished. In addition, adjustment for established risk factors also abolished the association between PLP and risk of MI.


CONCLUSION
These findings from a prospective German cohort study suggest that PLP is not independently associated with risk of MI.