Aspirin intake and the use of serum ferritin as a measure of iron status

Background: Atherosclerosis, a primary cause of myocardial infarction (MI), is an inflammatory disease. Aspirin use lowers risk of MI, probably throug h antithrombotic and antiinflammatory effects. Because serum ferritin (SF) can be elevated spuriously by inflammation, reported associations between e levated SF. used as an indicator of iron stores, and heart disease could be confounded by occult inflammation and aspirin use if they affect SF indepe ndently of iron status. Objective: We tested the hypothesis that aspirin use is associated with red uced SF. Design: We used analysis of covariance to investigate the relation between SF and categories of aspirin use in 913 elderly participants aged 67-96 y i n the Framingham Heart Study. Results: After adjustment for sex, age, body mass index, smoking, alcohol u se. concentrations of C-reactive protein and liver enzymes, white blood cel l count, and use of nonaspirin nonsteroidal antiinflammatory drugs and othe r medications, subjects who took >7 aspirins/wk had a significantly lower ( by 25%) geometric mean SF than did nonusers, who took < 1 aspirin/wk (71 co mpared with 95 mug/L, respectively, P for trend = 0.004). This effect of as pirin on SF was more marked in diseased subjects than in healthy subjects ( mean SF was 50% lower compared with 21% lower. respectively). Conclusions: Aspirin use is associated with lower SF. We suggest this effec t results from possible increased occult blood loss and a cytokine-mediated effect on SF in subjects with inflammation, infection, or liver disease. T he relations between aspirin, inflammation, and SF may confound epidemiolog ic associations between elevated SF, as an indicator of iron stores, and he art disease risk.