Here's a situation many people find themselves in today - your doctor has measured your C-reactive protein (CRP) level, and found it to be elevated. (Read here about when to have your CRP measured.)
It is likely that you may be puzzled, or even alarmed, by this finding. Unfortunately, it is reasonably likely that your doctor is also puzzled about what to do next - since "what to do next" is not entirely straightforward. Still, there is a way to assess the most reasonable next steps.
Now that you know your CRP is high, there are two questions you should be asking.
1) What are my other risk factors?
Elevated CRP levels are almost always associated with other risk factors for heart disease. These include smoking, obesity, sedentary lifestyle, increased cholesterol, hypertension and metabolic syndrome. One thing you know for sure is that, whatever you thought your cardiac risk was before the CRP was measured, now it's higher. So, whatever you and your doctor may decide to do about the CRP itself, clearly you need to take aggressive measures to reduce all your cardiac risk factors.
2) How can I reduce my CRP level?
Several ways of reducing CRP have been identified.
Non-pharmacological methods of reducing CRP include aerobic exercise, smoking cessation, weight loss and diet. In one study, healthy adults eating either a standard low saturated fat diet or the same diet plus plant sterols, soy protein, and nuts both had reductions in CRP levels. However, those on the plant sterol diet had a greater reduction. In another study that enrolled severely obese patients, reductions in CRP were achieved with either a fat restricted or carbohydrate restricted diet; however, the low-carb diet seemed to be more effective in reducing CRP
Drug therapy can also reduce CRP. Statins reduce CRP levels significantly (13 to 50%,) according to several clinical trials. Lipitor (atorvastatin), Mevacor (lovastatin), Pravachol (pravastatin), Crestor (rosuvastatin) and Zocor (simvastatin) have all been proven to bring down CRP levels, and have shown evidence of reducing cardiac risk through CRP (as opposed to cholesterol) reduction. And recently, the JUPITER trial showed definitively that in patients with high CRP levels but "normal" cholesterol levels, Crestor significantly and substantially reduced cardiovascular risk.
While aspirin does not reduce CRP levels, patients with elevated CRP levels gain more risk-reduction benefit from aspirin than those with normal CRP levels. So elevated CRP levels may tip the scales in favor of prophylactic aspirin therapy for some. Read about who should take prophylactic aspirin.
The bottom lineIt remains unknown whether CRP itself increases risk, or whether it merely reflects the vascular injury and inflammation that results from other risk factors. So if your CRP levels are elevated, you should definitely attempt to reduce all your cardiac risk factors by exercising, not smoking, losing weight, watching your diet, and controlling your blood pressure. (Read more here about reducing your cardiac risk.)
However, it now appears clear that the use of statin drugs can substantially reduce the risk of heart attack and stroke in even healthy-appearing patients whose CRP levels are high. If you have high CRP levels, especially if you have one or more additional risk factors for heart disease, you should discuss the option of taking a statin drug with your doctor.
Cook NR, Buring JE, and Ridker PM. The effect of including C-reactive protein in cardiovascular risk prediction models for women. Ann Intern Med 2006; 145:21-29.
Lloyd-Jones DM, Liu K, Tian L, and Greenland P. Narrative review: Assessment of C-reactive protein in risk prediction for cardiovascular disease. Ann Intern Med 2006; 145:35-42.
Davey Smith G, Timpson N and Lawlor D. C-reactive protein and cardiovascular disease risk: Still an unknown quantity? Ann Intern Med 2006; 145:70-72.
Ridker PM, Danielson E, Fonseca FA et al. Rosuvastatin to prevent vascular events in men and women with elevated C-reactive protein. New Engl J Med 2008; DOI: 10.1056/NEJMoa0807646. Available at: http://www.nejm.org.