Low serum folate concentrations are associated with an excess incidence ofacute coronary events: the Kuopio Ischaemic Heart Disease Risk Factor Study

Objective: To test the hypothesis that low: serum folate concentrations are associated with an increased risk of acute coronary events in men free of prior coronary heart disease. Setting: Research Institute of Public Health, University of Kuopio, Kuopio, Finland. Design: Prospective study in a cohort of 734 men aged 46-64 y examined in 1 991-1993 as part of the Kuopio Ischaemic Heart Disease Risk Factor Study (K IHD) and followed for 5 y and 3 months. Intervention: Acute coronary events during the follow-up period were obtain ed by national hospital discharge registry. Baseline serum folate concentra tions were measured by radioimmunoassay. Results: During the follow-up, six (2.5%) men with higher serum folate conc entrations (highest third >11.3 nmol/l) and 28 (5.7%) men with lower serum folate (two lowest thirds) developed an acute coronary event (P = 0.008). I n a Cox model adjusting for age, examination years, and plasma lycopene con centration, in men with higher serum folate concentrations the relative ris k for an acute coronary event was 0.31 (95% CI 0.11-0.90, P = 0.031) when c ompared with men with lower serum folates. Conclusion: This prospective cohort study in middle-aged men from eastern F inland indicates that moderate-to-high levels of serum folate are associate d with a greatly reduced incidence of acute coronary events.