Does C-reactive protein predict cardiovascular events in women better than LDL?

Stevermer, James

Q&A

Does C-reactive protein predict cardiovascular events in women better than LDL?

J Fam Pract. 2003 March;52(3):183-200

By

James J. Stevermer, MD, MSPH

BACKGROUND: A growing body of evidence suggests an important role for inflammation in cardiovascular disease. Nested case-control studies have shown a consistent association between CRP and cardiovascular events such as stroke or myocardial infarction (MI). People in the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/ TexCAPS) were most likely to have benefit from lovastatin if they had elevated CRP.²
POPULATION STUDIED: The subjects were women enrolled in the Women’s Health Study, an ongoing trial evaluating aspirin and vitamin E for the primary prevention of MI. These women were all older than 45 when enrolled from 1992 to 1995. There were 28,345 women who had blood drawn at the onset of the trial, but only 27,939 women (with a mean age of 54.7 years) had samples that could be evaluated. Forty percent were using hormone replacement therapy (HRT), 25% had hypertension, 12% were smokers, and 2.5% were diabetic.
STUDY DESIGN AND VALIDITY: This prospective cohort study followed the women for a mean of 8 years. Cholesterol and CRP levels from the more than 15,000 women not on HRT were used to create the population-based distributions. The researchers found the crude and risk-adjusted hazard ratio for each quintile of CRP levels compared with the lowest quintile value. They also evaluated the additive predictive properties of CRP, as well as LDL cholesterol, and measured the effect of adjusting the Framingham 10-year cardiovascular risk score with CRP levels.
OUTCOMES MEASURED: The primary outcome was the ability to predict the occurrence of a first cardiovascular event, defined as nonfatal MI, nonfatal ischemic stroke, coronary revascularization procedures, or death from a cardiovascular disease. Standard definitions were used to determine whether patients had these events. They also analyzed the risks for developing each type of event individually.
RESULTS: The median CRP level was 1.52 mg/L and the median LDL was 123.7 mg/dL. The risk for a first cardiovascular event was linearly associated with increasing CRP levels. The adjusted relative risk of first cardiovascular event for increasing quintiles of CRP was 1.0 (the lowest quintile serves as the reference), 1.4, 1.6, 2.0, and 2.3. The adjusted risk for increasing quintiles of LDL was 1.0 (reference), 0.9, 1.1, 1.3 and 1.5. These findings are consistent with each type of event (stroke, MI, etc) as well as being independent of HRT usage.

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Does C-reactive protein predict cardiovascular events in women better than LDL?

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