Genetic variation in the natriuretic peptide system, circulating natriuretic peptide levels, and blood pressure: an ambulatory blood pressure study.

BACKGROUND In a large collaborative study (n > 50,000), common variants in the natriuretic peptide (NP) genes were found to be associated with circulating NP levels and also with blood pressure (BP) levels based on office BP measurements (OBPMs). It is unknown if determining an individual's BP by 24-h ambulatory BP measurements (ABPMs) will influence the effect of NP gene variations on BP levels. METHODS We used rs632793 at the NPPB (NP precursor B) locus to investigate the relationship between genetically determined serum N-terminal pro-brain NP (NT-proBNP) concentrations and BP levels determined by both 24-h ABPMs and OBPMs in a population consisting of 1,397 generally healthy individuals taking no BP-lowering drugs. RESULTS rs632793 was significantly correlated with serum Nt-proBNP levels (r = 0.10, P = 0.0003), and participants with the A:A genotype had lower serum Nt-proBNP levels than participants with the G:G genotype (geometric mean (95% confidence interval (CI)): 34.8 (31.5-38.4) pg/ml vs. 48.1 (41.9-55.3) pg/ml, P = 0.0002), but higher 24-h ambulatory BP levels (mean difference (95% CI): 2.0 (0.1-4.1) mm Hg, P = 0.043, for systolic BP and 1.7 (0.4-3.1) mm Hg, P = 0.011, for diastolic BP). Office BP decreased across the genotypes from A:A to G:G, but the differences did not reach statistical significance (P ≥ 0.12). CONCLUSIONS This study suggests that 24-h ABPMs is a better method than OBPMs to detect significant differences in BP levels related to genetic variance and provides further evidence that the NP system plays an important role in BP regulation.