NEW YORK (Reuters Health) – Elevated levels of high-sensitivity C-reactive protein (hsCRP), an inflammatory marker, predicted mortality and myocardial infarction but not stroke in a multiethnic cohort.

“Our study population is unique in that it includes a multiethnic population with a high proportion of Hispanics,” lead author Dr. Mitchell S. V. Elkind, from Columbia University College of Physicians and Surgeons, New York, told Reuters Health. “These people have a high burden of risk factors, like hypertension and diabetes.”

In contrast to other studies of CRP, which have mostly focused on younger, healthier people, “ours shows that among multiethnic, urban populations, CRP may be less useful as a marker of stroke risk, though it still seems to predict heart attack and death,” he noted.

The Northern Manhattan Study is a prospective community-based investigation looking at stroke rates and risk factors in men and women at least 40 years of age. The 2240 subjects had hsCRP measured at baseline and were followed for a median of 7.9 years. The cohort was 64.2% female, 23.5% black, and 55.1% Hispanic, and the average age was 68.9 years.

After adjusting for demographics, an hsCRP level of >3 mg/L was associated with a 60% increased risk for stroke relative to a level of <1 mg/L. After accounting for known stroke risk factors, however, the association was weakened and not statistically significant. Dr. Elkind said his team was “surprised by the finding that CRP was not an important predictor of stroke. I think we did not find this association between CRP and stroke because of the already elevated risk among people in our study, so that CRP did not add much additional value.” Consistent with prior research, elevated hsCRP levels were linked to MI (HR = 1.70) and mortality (HR = 1.54). The authors also found no evidence that levels of serum amyloid A, another inflammatory biomarker, were predictive of stroke. Regarding future research, Dr. Elkind commented, “We are continuing to do studies of other biomarkers, which may be more informative for stroke than is CRP, and we are also continuing to evaluate the utility of CRP and other markers after a stroke has already occurred, as a way of predicting and potentially preventing recurrence.” Reference:
Neurology 2009;73:1300-1307.