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

Abstract

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 1991-1993 as part of the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) and followed for 5 y and 3 months.

Intervention: Acute coronary events during the follow-up period were obtained by national hospital discharge registry. Baseline serum folate concentrations were measured by radioimmunoassay.

Results: During the follow-up, six (2.5%) men with higher serum folate concentrations (highest third>11.3 nmol/1) and 28 (5.7%) men with lower serum folate (two lowest thirds) developed an acute coronary event (P=0.008). In a Cox model adjusting for age, examination years, and plasma lycopene concentration, in men with higher serum folate concentrations the relative risk for an acute coronary event was 0.31 (95% CI 0.11-0.90, P=0.031) when compared with men with lower serum folates.

Conclusion: This prospective cohort study in middle-aged men from eastern Finland indicates that moderate-to-high levels of serum folate are associated with a greatly reduced incidence of acute coronary events.