Reference Limits for N-terminal-pro-B-type Natriuretic Peptide in Healthy Individuals (From the Framingham Heart Study)

摘要

N-terminal-pro-B-type natriuretic peptide (NT-proBNP) is a commonly measured cardiovascular biomarker in both ambulatory and hospital settings. Nonetheless, there are limited data regarding “normal” ranges for NT-proBNP in healthy individuals, despite the importance of such information for interpreting natriuretic peptide measurements. We examined a healthy reference sample free of cardiovascular disease from the Framingham Heart Study Generation 3 cohort; there were 2,285 subjects (mean age 38 years, 56% women). Plasma NT-proBNP levels were measured using the Roche Diagnostics Elecsys 2010 assay, and reference values (2.5, 50, 97.5 quantiles) were determined using empiric and quantile regression methods. Gender, age, and body mass index accounted for approximately 33% of the inter-individual variability in NT-proBNP in the reference sample. NT-proBNP values were substantially higher in women compared with men at every age, and levels increased with increasing age for both sexes. Using quantile regression, the upper reference values (97.5 quantile) for NT-proBNP were 42.5 pg/ml to 106.4 pg/ml in men (depending on age), and 111.0 pg/ml to 215.9 pg/ml in women. Intra-individual variability was assessed in an additional 12 healthy individuals, who had serial NT-proBNP measurements over a month. Intra-class correlation was 0.85, indicating that most of the variability in NT-proBNP concentrations was among-persons rather than within-persons. However, the reference change value was 100%, suggesting that small proportional differences in NT-proBNP could be attributable to analytic variability. In conclusion, the reference limits obtained from this large, healthy community-based sample may aid in the evaluation of NT-proBNP concentrations measured for both clinical and research purposes.