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

Abstract

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. Research Institute of Public Health, University of Kuopio, Kuopio, Finland. 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. Acute coronary events during the follow-up period were obtained by national hospital discharge registry. Baseline serum folate concentrations were measured by radioimmunoassay. 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. 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.