Is C-reactive protein an independent risk factor for essential hypertension?

Context. C-reactive protein (CRP), predicts coronary heart disease incidence in healthy subjects and has been associated with decreased endothelium-dependent relaxation, a potential risk factor for hypertension. However, the relationship between CRP and hypertension has not been studied. Objective. To assess whether circulating levels of CRP are independently related to essential hypertension. Design. Cross-sectional population survey. We measured circulating levels of CRP, blood pressure and cardiovascular risk factors among participants. Binomial regression was used to calculate the adjusted effect of CRP on the prevalence of hypertension. Setting. General community of Bucaramanga, Colombia. Participants. A random sample of 300 subjects ≥ 30 years old. Main outcome measure. Arterial blood pressure. Results. Overall hypertension prevalence was 46.0%. The unadjusted prevalence of hypertension was 58.7% in the highest quartile of CRP, but only 34.7% in the lowest quartile. After adjustment for age, sex, body mass index, family history of hypertension, fasting glycemia, sedentary behaviour, and alcohol consumption, the prevalence of hypertension was 1.14 [95% confidence interval (CI), 0.82, 1.58; P= 0.442], 1.36 (95% CI, 0.99, 1.87; P= 0.057) and 1.56 (95% CI, 1.14, 2.13; P= 0.005) times higher in subjects in the second, third and fourth quartiles of CRP, as compared to subjects in the first quartile. Conclusions. Our results suggest, for the first time, that CRP level may be an independent risk factor for the development of hypertension. However, because of the cross-sectional nature of our study, this finding should be confirmed in prospective cohort studies, aimed at elucidating the role of CRP in the prediction, diagnosis and management of hypertension.