Lipids, atherosclerosis and CVD risk: is CRP an innocent bystander?
OBJECTIVE
To evaluate recent human studies with respect to the interpretation of whether elevated plasma levels of C-reactive protein (CRP) cause cardiovascular disease (CVD), or whether elevated CRP levels more likely is an innocent bystander.


RESULTS
Elevated CRP concentrations are consistently associated with CVD risk. A recent study showed that aggressive statin treatment caused reductions of 50% in LDL cholesterol, 37% in CRP, 44% in CVD events, and 20% in total mortality, and that the highest treatment benefits were obtained in those with the lowest achieved levels of both LDL cholesterol and CRP. However, a reduction in CRP levels after statin treatment could be secondary to the reduced LDL cholesterol levels, and thereby less inflammation in atherosclerotic plaques. We recently performed 4 large Mendelian randomization studies, studies that demonstrated that elevated CRP associate with increased risk of CVD, that genetic variation in the CRP gene associate with increased CRP levels, but that this genetic variation in the CRP gene do not associate with increased risk of CVD. In contrast to previous studies, these new studies had enough statistical power to effectively exclude that genetically elevated CRP cause CVD.


CONCLUSIONS
These data suggest that elevated CRP per se does not cause CVD; however, inflammation per se possibly contributes to CVD. Elevated CRP levels more likely is a marker for the extent of atherosclerosis or for the inflammatory activity and vulnerability of atherosclerotic plaques, and thus simply an innocent bystander in CVD.
Nordestgaard
B G
BG
Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital Herlev Ringvej 75, DK 2730 Herlev, Denmark. brno@heh.regionh.dk
Zacho
J
J
D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D050197:Atherosclerosis / Q000097:blood / Q000150:complications* / Q000188:drug therapy / Q000235:genetics; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000235:genetics / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology* / Q000235:genetics / Q000517:prevention & control; D050171:Dyslipidemias / Q000097:blood / Q000150:complications* / Q000188:drug therapy; D019317:Evidence-Based Medicine; D020022:Genetic Predisposition to Disease; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D018836:Inflammation Mediators / Q000097:blood*; D008055:Lipids / Q000097:blood*; D010641:Phenotype; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012307:Risk Factors; D015854:Up-Regulation
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D018836:Inflammation Mediators; D008055:Lipids; D002097:C-Reactive Protein