Real-World Distribution of NT-proBNP and Its Association with Age and Cardiovascular Disease in an Iranian Tertiary Hospital

Background : Interpretation of N-terminal pro-B-type natriuretic peptide (NT-proBNP) tests is influenced by demographic and clinical characteristics. However, data describing its distribution in Iranian hospital-based populations are scarce. This study evaluated NT-proBNP concentrations and their associations with age, sex, and documented cardiovascular disease (CVD) in routine clinical practice. Methods : In this cross-sectional study, 527 consecutive individuals who underwent NT-proBNP testing at the Masih Daneshvari Hospital between March and August 2025 were enrolled. Whole blood lithium-heparin samples were analyzed using the Roche Cobas h232 analyzer. Because NT-proBNP values were non-normally distributed, Mann–Whitney U and Kruskal–Wallis tests with Bonferroni-adjusted post-hoc comparisons were applied. Results : The median NT-proBNP concentration was 659 pg/mL (IQR: 2755-150pg/mL), Participants with documented CVD (IQR: 8161-915pg/ml) had significantly higher NT-proBNP levels than those without documented CVD (IQR: 2299-130 pg/mL,P<0.0001)). NT-proBNP concentrations increased significantly across age groups irrespective of the presence of CVD, reaching the highest levels in individuals older than 75 years (IQR: 3620-371 pg/ml P <0.001) compared to subjects <50 years (IQR: 2641-172 pg/ml,) whereas no significant sex-related difference was observed (P=0.264). Conclusions : NT-proBNP concentrations in this hospital-based Iranian population were primarily influenced by age and the presence of documented CVD rather than sex. These findings provide locally derived evidence that may support more appropriate interpretation of NT-proBNP results in routine clinical practice and serve as a foundation for establishing population-specific reference values for future multicenter studies .