Background: Accumulating data suggest a link between blood pressure and vascular inflammation.
Methods and results: We examined the relationship between blood pressure, C-reactive protein (CRP), and incident first cardiovascular events among 15 215 women followed prospectively over a median of 8.1 years. In cross-sectional analyses at baseline, median levels of CRP for women with blood pressure <120/75, 120 to 129/75 to 84, 130 to 139/85 to 89, 140 to 159/90 to 94, and > or =160/95 mm Hg were 0.96, 1.42, 2.20, 2.82, and 3.34 mg/L, respectively (P for trend <0.0001). Increasing categories of blood pressure were significant predictors of CRP levels at baseline. In prospective analyses, both elevated CRP levels (> or =3 mg/L) and increasing categories of blood pressure were independent determinants of future cardiovascular events, and CRP had incremental prognostic value at all levels of blood pressure. The adjusted hazard ratio for women with blood pressure > or =160/95 mm Hg and CRP levels > or =3 mg/L was 8.31 (95% CI, 4.44 to 15.55, P<0.0001) compared with those with blood pressure <120/75 and CRP levels <3 mg/L. After participants had been divided into 4 groups on the basis of CRP levels (<3 or > or =3 mg/L) and blood pressure levels (<130/85 or > or =130/85), the risk factor-adjusted hazard ratios were as follows: low CRP/low blood pressure, 1.0; high CRP/low blood pressure, 1.87 (P=0.002); low CRP/high blood pressure, 2.54 (P<0.0001); and high CRP/high blood pressure, 3.27 (P<0.0001).
Conclusions: CRP and blood pressure are independent determinants of cardiovascular risk, and their predictive value is additive.