Peripheral inflammatory biomarkers for myocardial infarction risk: A prospective community-based study

Background: Most previous studies regarding chronic inflammation and risk of myocardial infarction (MI) have lacked repeated measures of high-sensitivity Creactive protein (hs-CRP) and/or white blood cell (WBC) count over time. We examined whether cumulative average and longitudinal changes in these biomarkers were associated with subsequent MI risk. Methods: In this prospective, community-based study, we included 82544 Chinese participants [66796 men and 15748 women; mean (SD) age 55.1 (9.86) y] without prior cardiovascular diseases or cancer at baseline (2006-2007). hs-CRP, WBC and other clinical covariates were assessed at baseline and every 2 years during follow-up. Results: During 6 years of follow-up (2006-2012), we documented 714 incident MI cases. Higher baseline and cumulative average concentrations of hs-CRP and/or WBC were consistently associated with increased risk of MI (P_trend < 0.001 for both). Longitudinal increase in hs-CRP (P_trend < 0.001), but not WBC, was also associated with a higher future risk of MI, after adjustment for their baseline values and other covariates. Each 1-mg/L increment per year in hs-CRP was associated with a 9.3% increase in risk for future MI [hazard ratio (HR) = 1.09, 95% CI, 1.03; 1.17]. Participants with high-grade inflammatory status (hs-CRP ≥10 mg/L and WBC ≥10 × 10⁹/L) had a higher risk of MI occurring <3 months after hs-CRP/WBC assessments vs those with hs-CRP <0.5 mg/L and WBC <5 × 10⁹/L (HR = 6.64; 95% CI, 1.49-29.6), as compared with MI occurring ≥4 years (HR = 2.95; 95% CI, 0.90, 9.65). Conclusions: Plasma hs-CRP concentration and WBC predicted MI risk. Longitudinal increase in hs-CRP was also associated with a higher risk of MI.