C-Reactive Protein and B-Type Natriuretic Peptides in Never-Treated White Coat Hypertensives

Abstract

Arterial hypertension has been associated with increased plasma concentrations of C-reactive protein (CRP) and B-type natriuretic peptide (BNP). This study tested the hypothesis that patients with white coat hypertension have lower plasma CRP and BNP concentrations than those with sustained hypertension. A total of 109 consecutive medical outpatients with never-treated office hypertension underwent ambulatory blood pressure monitoring and blood sampling to determine CRP and BNP concentrations. Patients with treated hypertension, lipid-lowering therapy, renal insufficiency or structural heart disease other than left ventricular hypertrophy were excluded. White coat hypertension was defined as office hypertension associated with mean daytime blood pressure values below 135/85 mmHg. A control group of 48 consecutive, age- and sex-matched patients without office hypertension were recruited during the same period. Twenty-six patients (24%) had white coat hypertension. There were no statistically significant differences in baseline variables between patients with sustained hypertension and white coat hypertensives, except for mean blood pressure values. Mean CRP was 3.2±5.1 mg/l in patients with white coat hypertension compared to 3.4±4.2 mg/l in those with sustained hypertension (p=0.79). Control patients had significantly lower CRP values than patients with either white coat or sustained hypertension (1.2±0.9 mg/l, p=0.002 and p=0.038, respectively). Mean BNP concentrations were 21±25 pg/l and 44±125 pg/l in white coat and sustained hypertensives, respectively (p=0.36). The plasma concentrations of CRP and BNP did not differ between patients with white coat hypertension and those with sustained hypertension.