Effect of short-term aspirin use on C-reactive protein

Markers of inflammation, such as C-reactive protein (CRP) and fibrinogen, h ave been shown to be predictive of cardiovascular disease. In the Physician s Health Study, the magnitude of reduction in the risk of myocardial infarc tion with aspirin therapy was related to baseline CRP levels, raising the p ossibility that the protective effect of aspirin may be due to antiinflamma tory properties in addition to its antiplatelet effect. We therefore invest igated whether aspirin therapy lowers CRP levels. Because heavy physical ex ertion is a well-known trigger of myocardial infarction, we also investigat ed the effect of aspirin on CRP levels before and after strenuous exercise. Thirty-two healthy men, aged 29 +/- 6 years, were enrolled in a randomized , double-blind, parallel study. Blood samples were obtained immediately bef ore and after maximal treadmill exercise at baseline and following 7 days o f aspirin therapy (81 or 325 mg). The levels of CRP, as measured by ELISA, increased by 13% following exercise (P < 0.0001). However, aspirin did not significantly alter CRP levels, either at rest (0.81 +/- 0.13 mg/L before a spirin vs. 0.78 +/- 0.13 mg/L on aspirin) or following exercise (0.92 +/- 0 .13 mg/L before aspirin vs. 0.86 +/- 0.13 mg/L on aspirin), P = 0.73. When the resting and postexercise data were combined, the levels were 0.87 +/- 0 .13 mg/L before aspirin and 0.82 +/- 0.13 mg/L on aspirin (a nonsignificant 6% reduction, P = 0.20). In conclusion, in healthy male subjects CRP level s were not significantly reduced by short-term aspirin therapy. Our data, t aking together with other reports, suggest that aspirin may not affect the levels of inflammatory markers. However, further studies are needed with a longer duration of therapy, among subjects with coronary heart disease, and using additional markers of inflammation besides CRP to determine the long -term effects of aspirin use.