Background: Secretion of natriuretic peptides is related to cardiac wall stress and influenced by the renin-angiotensin system. Therefore, we investigated the influence of blood pressure (BP) reduction with losartan versus atenolol on N-terminal pro-atrial natriuretic peptide (Nt-proANP) and N-terminal pro-brain natriuretic peptide (Nt-proBNP).
Methods: In 183 patients with hypertension and electrocardiographic left ventricular (LV) hypertrophy, enrolled in the LIFE Study, we measured BP and serum Nt-proANP and Nt-proBNP by immunoassay after 2 weeks of placebo treatment and after 1, 2, 4, 6, 12, 24, 36 and 48 months of randomized treatment with losartan- or atenolol-based antihypertensive regimens.
Results: There was no significant difference in BP at any time point between the two treatment groups. In patients treated with losartan, median Nt-proANP decreased gradually throughout the study, reaching significance after 6 months of treatment (1125-1060 pmol/l, P < 0.001), and Nt-proBNP decreased within the first month (24.7-18.7 pmol/l, P < 0.01) and stayed reduced throughout the study. During losartan-based antihypertensive treatment, Nt-proANP and Nt-proBNP as a percentage of baseline values were correlated to reductions in systolic BP (r = 0.11, P < 0.01 and r = 0.10, P = 0.01) and diastolic BP (r = 0.17, P < 0.001 and r = 0.07, P = 0.09). In atenolol-treated patients, Nt-proANP (1100-1640 pmol/l, P < 0.001) and Nt-proBNP (20.0-37.7 pmol/l, P < 0.001) increased during the first month, and remained elevated throughout the study. During atenolol-based antihypertensive treatment, changes in Nt-proANP (r = -0.16, P < 0.001) and Nt-proBNP (r = -0.07, P = 0.08) were negatively related to change in heart rate.
Conclusion: Nt-proANP and Nt-proBNP were reduced in parallel with BP in losartan-treated patients whereas they increased in parallel with decreased heart rate in atenolol-treated patients.