Increased C-reactive protein concentrations in never-treated hypertension: the role of systolic and pulse pressures

OBJECTIVE: To test whether the plasma concentration of C-reactive protein (CRP), a sensitive marker of systemic inflammation, is increased in patients with newly diagnosed, never-treated hypertension and whether blood pressure and its pulsatile component, pulse pressure, are correlated with plasma CRP concentration independently of a consistent number of cardiovascular risk factors. DESIGN: Cross-sectional study in a hospital outpatient hypertension clinic. METHODS: A total of 135 newly diagnosed, never-treated patients with hypertension and 40 healthy matched non-hypertensive controls underwent office and 24-h blood pressure measurement and blood sampling for determination of plasma CRP and serum lipid concentrations. RESULTS: Plasma CRP concentration was greater in hypertensive individuals (1.85 mg/l, interquartile range 0.74-3.64) than in control individuals (1.01 mg/l, interquartile range 0.67-1.88; P = 0.02). In the entire population, CRP had a significant direct association with office systolic blood pressure and pulse pressure, but not with diastolic blood pressure. Among hypertensive patients, plasma CRP was related to 24-h systolic blood pressure (r = 0.28, P < 0.01) and pulse pressure (r = 0.32, P < 0.01), but not to diastolic blood pressure (r = 0.12, P > 0.2). CRP was also directly associated with body mass index (r = 0.25, P < 0.01), serum low-density lipoprotein cholesterol (r = 0.21, P = 0.03) and serum triglycerides (r = 0.21, P = 0.03). In the multivariate analysis, systolic blood pressure and pulse pressure, but not diastolic blood pressure, were significant predictors of plasma CRP concentration when a consistent number of cardiovascular risk factors was controlled for simultaneously. CONCLUSIONS: Systolic blood pressure and pulse pressure, but not diastolic blood pressure, are predictors of plasma C-reactive protein concentrations in patients with newly diagnosed, never-treated hypertension, irrespective of the potential proinflammatory action of traditional cardiovascular risk factors.