Stroke Incidence and High-Sensitivity C-Reactive Protein Among African Americans: The Jackson Heart Study.

Abstract

Background: Strokes are a leading cause of death and disability among African Americans in the United States. Biological markers to predict stroke remain elusive; thus, our objective was to investigate whether inflammation, as measured by high-sensitivity C-reactive protein (hs-CRP), was associated with stroke incidence among African Americans enrolled in the Jackson Heart Study (JHS).

Methods: Baseline hs-CRP levels were categorized in quintiles: quintile 1 (0.0084 mg/L); quintile 2 (0.0085-0.0189 mg/L); quintile 3 (0.0190-0.036 mg/L); quintile 4 (0.037-0.0675 mg/L); quintile 5 (≥0.0676 mg/L). Nonfatal stroke incidence was ascertained from passive community surveillance through annual phone calls and adjudicated via hospital records. At baseline, stroke risk factors/covariates were compared across quintiles using a one-way analysis of variance and a chi-square test. The association between baseline hs-CRP levels and stroke incidence was determined using a Cox regression analysis to estimate hazard ratios (HRs) and 95% confidence intervals (CI).

Results: In the unadjusted model, hs-CRP levels in quintile 2 (HR, 1.48; 95% CI, 0.96-2.29), quintile 3 (HR, 1.44; 95% CI, 0.93-2.24), and quintile 4 (HR, 1.09; 95% CI, 0.68-1.74) were not associated with stroke incidence when compared with quintile 1 (reference). However, individuals within quintile 5 (HR, 1.78; 95% CI, 1.17-2.72) exhibited a significantly increased risk for stroke compared with those in the reference quintile. This risk persisted after adjusting for stroke risk factors (demographics, anthropometrics, health condition covariates, health behavioral risk factors, and cardiovascular disease history) for quintile 5 (HR, 1.87; 95% CI, 1.17-2.98) compared with reference quintile 1.

Conclusions: An increased and independent risk of nonfatal stroke appears at the highest quintile of hs-CRP values (≥0.0676 mg/L) among JHS participants.