Clinical relevance of biological variation: the lesson of brain natriuretic peptide (BNP) and NT-proBNP assay

摘要

The cardiac natriuretic peptides (NPs), ANP and BNP, have a very large intra-individual biological variation (CV_i) in both healthy subjects and patients with heart failure (HF). Stimulation by hemodynamic overload (cardiomyocyte stretch) and by neuroendocrine α-ad-renergic agonists, angiotensin II, endothelins, vasopres-sin), immunological agents and growth factors modulates the production of NPs by the heart and forms a negative feedback system with the counter-regulatory neurohormonal system. CV_i is a mirror of variation in neuroendocrine network activity enlarged by the dependence on age (decline in myocardial function) and gender (BNP concentrations are 36% higher in women than in men < 50 years). The two counterregulatory systems maintains homeostasis by regulating heartbeat, plasma volume and vasomotion as indicators of healthy variability.