Brain natriuretic peptide and C-type natriuretic peptide are differently regulated by age but similarly elevated in coronary artery disease

OBJECTIVE: We investigated the effect of age and coronary angioplasty on brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP). METHODS AND RESULTS: Serum levels of both peptides immediately before catheterization and at the end of angioplasty in 15 patients (age 68 +/- 8 years, 8 men) with coronary artery disease (CAD) were compared to 12 elderly (65 +/- 7 years, 8 men) and 16 non-elderly (34 +/- 7 years, 10 men) healthy individuals. The results showed that in healthy individuals the levels of both peptides are age-dependent dissimilarly. Compared to the non-elderly, while BNP increases in the elderly (7.81 +/- 1.60 vs. 10.01 +/- 2.06 pg/ml, p = 0.002), CNP decreases (5.39 +/- 1.30 vs. 2.22 +/- 0.80 pg/ml, p < 0.001). On the other hand, compared to the elderly healthy persons, patients with CAD have a marked increase in the baseline levels of BNP (20.02 +/- 17.43 pg/ml, p = 0.03) and CNP (4.41 +/- 1.20 pg/ml, p < 0.001). However, both peptides remain stationary immediately after angioplasty (BNP, 21.02 +/- 16.95; CNP, 4.51 +/- 1.06 pg/ml; both p = 0.4). CONCLUSIONS: BNP and CNP are differentially regulated by age in a healthy state, suggesting that each peptide has a distinct role during the aging process. The elevation of both peptides in CAD but little change shortly after angioplasty may indicate that both peptides respond to a chronic state rather than an acute episode of vascular damage.