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 8 10 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.