LAUSR

BACKGROUND We hypothesized that circulating markers reflecting monocyte/macrophage and T cell activation are associated with increased risk of myocardial infarction (MI) in apparently healthy individuals. METHODS Serum monocyte/macrophage and T cell activation markers soluble (s) CD163, sCD14, Gal3BP, sCD25 and sCD166 were analyzed by enzyme-immunoassay in a case-control study nested within the population-based HUNT2 cohort in Norway. Among 58,761 apparently healthy men and women followed a median 11.3years, 1587 incident MI cases were registered, and compared to 3959 age- and sex-matched controls. RESULTS Higher serum sCD163 (Q4 vs. Q1 OR: 1.27, P-trend 0.002), sCD14 (Q4 vs. Q1 OR: 1.38, P-trend<0.001), and especially sCD25 (Q4 vs. Q1 OR: 1.45, P-trend<0.001), were associated with increased MI risk in the age-and sex adjusted models. However, after additional adjustment for cardiovascular risk factors these associations were strongly attenuated (Q4 vs Q1 ORs between 1.02 and 1.12, P-trends between 0.30 and 0.58). CONCLUSIONS sCD163, sCD14 and sCD25 may reflect leukocyte activation and inflammatory mechanisms related to atherogenesis, but do not predict MI risk above and beyond conventional cardiovascular risk factors.