title: Being Overweight Is Associated With Greater Survival in ICU Patients: Results From the Intensive Care Over Nations Audit.
abstract: OBJECTIVE
  To assess the effect of body mass index on ICU outcome and on the development of ICU-acquired infection.
  
  
  METHODS
  A substudy of the Intensive Care Over Nations audit.
  
  
  METHODS
  Seven hundred thirty ICUs in 84 countries.
  
  
  METHODS
  All adult ICU patients admitted between May 8 and 18, 2012, except those admitted for less than 24 hours for routine postoperative monitoring (n = 10,069). In this subanalysis, only patients with complete data on height and weight (measured or estimated) on ICU admission in order to calculate the body mass index were included (n = 8,829).
  
  
  METHODS
  None.
  
  
  RESULTS
  Underweight was defined as body mass index less than 18.5 kg/m, normal weight as body mass index 18.5-24.9 kg/m, overweight as body mass index 25-29.9 kg/m, obese as body mass index 30-39.9 kg/m, and morbidly obese as body mass index greater than or equal to 40 kg/m. The mean body mass index was 26.4 ± 6.5 kg/m. The ICU length of stay was similar among categories, but overweight and obese patients had longer hospital lengths of stay than patients with normal body mass index (10 [interquartile range, 5-21] and 11 [5-21] vs 9 [4-19] d; p < 0.01 pairwise). ICU mortality was lower in morbidly obese than in normal body mass index patients (11.2% vs 16.6%; p = 0.015). In-hospital mortality was lower in morbidly obese and overweight patients and higher in underweight patients than in those with normal body mass index. In a multilevel Cox proportional hazard analysis, underweight was independently associated with a higher hazard of 60-day in-hospital death (hazard ratio, 1.32; 95% CI, 1.05-1.65; p = 0.018), whereas overweight was associated with a lower hazard (hazard ratio, 0.79; 95% CI, 0.71-0.89; p < 0.001). No body mass index category was associated with an increased hazard of ICU-acquired infection.
  
  
  CONCLUSIONS
  In this large cohort of critically ill patients, underweight was independently associated with a higher hazard of 60-day in-hospital death and overweight with a lower hazard. None of the body mass index categories as independently associated with an increased hazard of infection during the ICU stay.
authors.affiliation: 1Department of Anesthesiology and Intensive Care, Friedrich-Schiller University, Jena, Germany. 2Department of Medicine, Medical College of Wisconsin, Milwaukee, WI. 3Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL. 4Intensive Care Unit, Santa Maria degli Angeli, Pordenone, Italy. 5Critical Care Department, Cliniques Universitaires St Luc, UCL, Brussels, Belgium. 6St. James's University Hospitals, Multidisciplinary Intensive Care Research Organization (MICRO), Trinity Center for Health Sciences, Dublin, Ireland. 7Critical Care Center, Corporacion Sanitaria Parc Taulí, CIBER Enfermedades Respiratorias, Parc Tauli, University Institute, Sabadell, Spain. 8Service de Réanimation Polyvalente, CHU Dupuytren, Limoges cedex, France. 9Service d'Anesthésie et de Réanimation, Hôpital Nord, Assistance Publique-Hôpitaux de Marseille, Aix Marseille Université, Marseille, France. 10Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Yasser
authors.initials: Y
authors.lastname: Sakr
authors.forename: Ilmi
authors.initials: I
authors.lastname: Alhussami
authors.forename: Rahul
authors.initials: R
authors.lastname: Nanchal
authors.forename: Richard G
authors.initials: RG
authors.lastname: Wunderink
authors.forename: Tommaso
authors.initials: T
authors.lastname: Pellis
authors.forename: Xavier
authors.initials: X
authors.lastname: Wittebole
authors.forename: Ignacio
authors.initials: I
authors.lastname: Martin-Loeches
authors.forename: Bruno
authors.initials: B
authors.lastname: François
authors.forename: Marc
authors.initials: M
authors.lastname: Leone
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016638:Critical Illness; D003428:Cross Infection / Q000453:epidemiology*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology* / Q000401:mortality; D016016:Proportional Hazards Models; D012720:Severity of Illness Index; D012737:Sex Factors; D013851:Thinness / Q000453:epidemiology