title: Relation of N-terminal pro-brain natriuretic peptide levels and their prognostic power in chronic stable heart failure to obesity status.
abstract: OBJECTIVE
  To investigate the relationship between body mass index (BMI) and N-terminal pro-brain natriuretic peptide (NTproBNP) level and resultant prognostic capacity in chronic heart failure (CHF) controlled for known confounders.
  
  
  RESULTS
  We formed 206 triplets of patients (n = 618) with stable systolic CHF matched with respect to age, sex, renal function (MDRD, modification of diet in renal disease formula), and NYHA class, each with a BMI >30 kg/m(2) (group 3), 20-24.9 kg/m(2) (group 1), and 25-29.9 kg/m(2) (group 2). BMI conveys a 4% drop in NTproBNP per unit increase. This influence remained significant after correction for age, sex, MDRD, NYHA, heart rate, rhythm, and ejection fraction. NTproBNP remained an independent predictor of adverse outcome after correction for age, sex, BMI, NYHA, MDRD, and ejection fraction. Despite numerical differences, prognostic power was comparable between BMI groups (log-transformed NTproBNP; group 1: hazard ratio (HR) 1.435, 95% CI 1.046-1.967, chi(2) 5.02, P = 0.03; group 2: HR 1.604, 95% CI 1.203-2.138, chi(2) 10.36, P = 0.001; group 3: HR 1.735, 95% CI 1.302-2.313, chi(2) 14.12, P = 0.0002) (P = NS, all). An NTproBNP correction factor was calculated.
  
  
  CONCLUSIONS
  Even matched for NYHA, age, sex, and renal function, BMI exerts a significant and independent inverse influence on NTproBNP in patients with stable CHF. NTproBNP retained equal statistical power in all three BMI groups.
authors.affiliation: Department of Cardiology, Angiology and Pulmonology, University of Heidelberg, INF 410, Heidelberg, Germany. lutz.frankenstein@med.uni-heidelberg.de
authors.forename: Lutz
authors.initials: L
authors.lastname: Frankenstein
authors.forename: Andrew
authors.initials: A
authors.lastname: Remppis
authors.forename: Manfred
authors.initials: M
authors.lastname: Nelles
authors.forename: Bernd
authors.initials: B
authors.lastname: Schaelling
authors.forename: Dieter
authors.initials: D
authors.lastname: Schellberg
authors.forename: Hugo
authors.initials: H
authors.lastname: Katus
authors.forename: Christian
authors.initials: C
authors.lastname: Zugck