title: Body mass index and mortality in acutely decompensated heart failure across the world: a global obesity paradox.
abstract: OBJECTIVE
  This study sought to define the relationship between body mass index (BMI) and mortality in heart failure (HF) across the world and to identify specific groups in whom BMI may differentially mediate risk.
  
  
  BACKGROUND
  Obesity is associated with incident HF, but it is paradoxically associated with better prognosis during chronic HF.
  
  
  METHODS
  We studied 6,142 patients with acute decompensated HF from 12 prospective observational cohorts followed-up across 4 continents. Primary outcome was all-cause mortality. Cox proportional hazards models and net reclassification index described associations of BMI with all-cause mortality.
  
  
  RESULTS
  Normal-weight patients (BMI 18.5 to 25 kg/m(2)) were older with more advanced HF and lower cardiometabolic risk. Despite worldwide heterogeneity in clinical features across obesity categories, a higher BMI remained associated with decreased 30-day and 1-year mortality (11% decrease at 30 days; 9% decrease at 1 year per 5 kg/m(2); p < 0.05), after adjustment for clinical risk. The BMI obtained at index admission provided effective 1-year risk reclassification beyond current markers of clinical risk (net reclassification index 0.119, p < 0.001). Notably, the "protective" association of BMI with mortality was confined to persons with older age (>75 years; hazard ratio [HR]: 0.82; p = 0.006), decreased cardiac function (ejection fraction <50%; HR: 0.85; p < 0.001), no diabetes (HR: 0.86; p < 0.001), and de novo HF (HR: 0.89; p = 0.004).
  
  
  CONCLUSIONS
  A lower BMI is associated with age, disease severity, and a higher risk of death in acute decompensated HF. The "obesity paradox" is confined to older persons, with decreased cardiac function, less cardiometabolic illness, and recent-onset HF, suggesting that aging, HF severity/chronicity, and metabolism may explain the obesity paradox.
authors: Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts.
authors: Ravi
authors: R
authors: Shah
authors: Department of Anesthesiology and Intensive Care, Lariboisière University Hospital, Assistance Publique-Hôpitaux de Paris, Université Paris Diderot, Paris, France.
authors: Etienne
authors: E
authors: Gayat
authors: Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts. Electronic address: jjanuzzi@partners.org.
authors: James L
authors: JL
authors: Januzzi
authors: Internal Medicine, Cardiology, and Intensive Care Medicine, Nippon Medical School Musashi-Kosugi Hospital, Tokyo, Japan.
authors: Naoki
authors: N
authors: Sato
authors: Biomarkers and Heart Diseases, UMR-942, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France.
authors: Alain
authors: A
authors: Cohen-Solal
authors: Emergency Department, Sant'Andrea Hospital, University La Sapienza, Rome, Italy.
authors: Salvatore
authors: S
authors: diSomma
authors: Sociedad Argentina de Cardiologia, Area de Investigacion SAC Azcuenaga, Buenos Aires, Argentina.
authors: Enrique
authors: E
authors: Fairman
authors: Division of Emergency Care, Helsinki University Central Hospital, Helsinki, Finland.
authors: Veli-Pekka
authors: VP
authors: Harjola
authors: Department of Cardiology, Steel Memorial Yawata Hospital, Kitakyushu, Japan.
authors: Shiro
authors: S
authors: Ishihara
authors: Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
authors: Johan
authors: J
authors: Lassus
authors: ANMCO Research Center, Firenze, Italy.
authors: Aldo
authors: A
authors: Maggioni
authors: Cardiology, Department of Experimental and Applied Medicine, University of Brescia, Brescia, Italy.
authors: Marco
authors: M
authors: Metra
authors: Department of Internal Medicine, University Hospital, Basel, Switzerland.
authors: Christian
authors: C
authors: Mueller
authors: Department of Laboratory Medicine, Konventhospital Barmherzige Brueder, Linz, Austria.
authors: Thomas
authors: T
authors: Mueller
authors: Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
authors: Jiri
authors: J
authors: Parenica
authors: Cardiology Service, Virgen de la Arrixaca Hospital, Department of Medicine, Faculty of Medicine, University Murcia, Murcia, Spain.
authors: Domingo
authors: D
authors: Pascual-Figal
authors: Baylor College of Medicine, Houston, Texas.
authors: William Frank
authors: WF
authors: Peacock
authors: Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
authors: Jindrich
authors: J
authors: Spinar
authors: University Medical Center, Utrecht, Utrecht, the Netherlands.
authors: Roland
authors: R
authors: van Kimmenade
authors: Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
authors: Alexandre
authors: A
authors: Mebazaa
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D014943:Global Health; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality*; D006801:Humans; D038622:Internationality; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis* / Q000401:mortality*; D011446:Prospective Studies; D012042:Registries
keywords: heart failure; obesity; obesity paradox