OBJECTIVETo investigate the plasma level of amino-terminal pro-brain natriuretic peptide (NT-proBNP) and related influencing factors in a community-based healthy population in Beijing area.

METHODSWe measured plasma NT-proBNP level by fluoroimmunoassay between March 2012 and July 2012 from 1 034 healthy subjects (including 486 men and 548 women). Empiric method was used to determine the reference value and influencing factors were analyzed.

RESULTSAge and gender are important factors affecting the level of NT-proBNP in healthy subjects. NT-proBNP plasma level is significantly higher in women than in men within each age strata below 75 years old, i.e. < 45, 45-54, 55-64 and 65-74 years old (P = 0.005, 0.001, 0.001, 0.011 respectively), but NT-proBNP plasma level is similar between male and female older than 75 years (P = 0.504). NT-proBNP level also increases with age irrespective of gender. Body mass index (BMI) is another independent influencing factor of NT-proBNP (P < 0.001), while estimated glomerular filtration rate is not influencing factor. The reference range of NT-proBNP is < 133 ng/L for men and < 289 ng/L for women aged < 55 years old, < 185 ng/L for men and < 333 ng/L for women aged between 55 and 64 years old, and < 465 ng/L for men and < 378 ng/L for women aged ≥ 75 years old.

CONCLUSIONThe major influencing factors of NT-proBNP level in the healthy population are age, gender and BMI. It essential to establish normal reference range of NT-proBNP according to these factors for Chinese population.