RESUMO
OBJECTIVE: To investigate plasma brain natriuretic peptide (BNP) concentrations in association with blood pressure (BP) at baseline and after antihypertensive drug treatment. PATIENTS AND METHODS: We prospectively examined 186 individuals with newly diagnosed essential hypertension without target organ damage, whose mean age was 48.7 +/- 10.9 years. Treatment initiation began with irbesartan 150 mg/day and was doubled at 4 weeks in cases of inadequate BP control. If indicated, at 8-week-follow-up hydrochlorothiazide 12.5 mg alone or with amlodipine 5-10 mg was added. BNP levels were measured at baseline and after 3 months of antihypertensive treatment. RESULTS: At baseline plasma BNP levels were found to be related to systolic BP (r = 0.27, P < 0.001), independent of age, sex, smoking status, BMI and left ventricular mass index estimated by echocardiography (beta = 11.81, SE = 3.82, P = 0.002). Additionally, higher BNP concentrations were observed in patients with stage 2 hypertension compared with those with stage 1 (median 38.9 vs. 29.9 pg/ml, P = 0.022). Multivariate analysis showed a positive association between BNP and systolic BP variability (beta = 0.03, SE = 0.01, P = 0.034). At follow-up, 64.7% of the participants who had achieved BP control showed decreased BNP levels in contrast to those with poor BP control (median change -14.5 vs. -1.3 and median range from -34.4 to -4.4 vs. -9.6 to 10.9, respectively, P < 0.001). CONCLUSION: In this hypertensive population, increased BNP concentrations are associated with higher BP levels and systolic BP variability. The fall of BNP observed in those who achieved BP control indicates that BNP could be used as a biochemical marker of effective BP control and target organ protection.
