C-reactive protein as a risk factor versus risk marker.

C-reactive protein (CRP) is consistently associated with cardiovascular disease in prospective and cross-sectional clinical and epidemiological studies. Inflammation is an important mechanism in cardiovascular disease, and the plasma level of CRP is considered to reflect the inflammatory condition of the patient and/or the vessel wall. In addition, there are also a number of indications for a causal role of CRP in cardiovascular disease. A number of new publications show potential causal effects of CRP on cardiovascular disease, and evidence from human-CRP transgenic animals also indicates a causal contribution of CRP to cardiovascular disease. On the other hand, a new large prospective study and an updated meta-analysis indicate that the contribution of CRP to cardiovascular disease is less impressive than reported earlier (odds ratio, 1.58; 95% confidence interval, 1.48-1.68). We review here the most recent evidence on mechanisms by which CRP is involved as a causal factor in the precipitation of cardiovascular disease. Evidence for such a role is accumulating.