title: Potent influence of obesity on suppression of plasma B-type natriuretic peptide levels in patients with acute heart failure: An approach using covariance structure analysis.
abstract: BACKGROUND
  Plasma B-type natriuretic peptide (BNP) levels may vary widely among patients with similar stages of heart failure, in whom obesity might be the only factor reducing plasma BNP levels. We investigated the effect of obesity and body mass index (BMI) on plasma BNP levels using serial measurements before and after treatment (pre- and post-BNP and pre- and post-BMI) in patients with acute heart failure.
  
  
  METHODS
  Multiple regression analysis and covariance structure analysis were performed to study the interactions between clinical factors in 372 patients. The pre-BMI was shown as a combination index of obesity and fluid accumulation, whereas the post-BMI was a conventional index of obesity.
  
  
  RESULTS
  There was a significant inverse correlation between BMI and BNP in each condition before and after treatment for heart failure. The direct significant associations of the log pre-BNP with the log post-BNP (β: 0.387), the post-BMI (β: -0.043), and the pre-BMI (β: 0.030) were analyzed by using structural equation modeling. The post-BMI was inversely correlated, but importantly, the pre-BMI was positively correlated, with the log pre-BNP, because the pre-BMI probably entailed an element of fluid accumulation. There were few patients with extremely high levels of pre-BNP among those with high post-BMI, due to suppressed secretion of BNP.
  
  
  CONCLUSIONS
  The low plasma BNP levels in true obesity patients with acute heart failure are of concern, because plasma BNP cannot increase in such patients.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kinoshita
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Japan. Electronic address: cadmk@jikei.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawai
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Minai
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Japan.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Yoshimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D006333:Heart Failure / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009765:Obesity / Q000378:metabolism*; D012044:Regression Analysis
chemical_list: D020097:Natriuretic Peptide, Brain
keywords: B-type natriuretic peptide; Biochemical marker; Body mass index; Covariance structure analysis; Fluid accumulation; Obesity