Yasser Sakr Christian Madl Daniela Filipescu Rui Moreno Johan Groeneveld Antonio Artigas Konrad Reinhart Jean-Louis Vincent Obesity is associated with increased morbidity but not mortality in critically ill patients Received: 9 November 2007 Accepted: 1 June 2008 Published online: 1 August 2008 Ó Springer-Verlag 2008 This article is discussed in the editorial available at doi:10.1007/s00134-008-1244-z Y. Sakr Á K. Reinhart Department of Anaesthesiology and Intensive Care, Friedrich-Schiller- University Jena, Jena, Germany C. Madl Intensive Care Unit 13H1, Department of Internal Medicine IV, Medical University of Vienna, Vienna, Austria D. Filipescu Department of Anesthesiology and Cardiac Intensive Care, Institute of Cardiovascular Diseases, Bucharest, Romania R. Moreno Department of Intensive Care, Hospital de St Antonio dos Capuchos, Lisbon, Portugal J. Groeneveld Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands A. Artigas Department of Intensive Care, Sabadell Hospital, Sabadell, Spain J.-L. Vincent ( ) ) Department of Intensive Care, Ho ˆpital Erasme, Universite ´ libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium e-mail: jlvincen@ulb.ac.be Tel.: +32-2-5553380 Fax: +3-22-5554555 Abstract Objective: To investi- gate the possible impact of obesity on morbidity and mortality in intensive care unit (ICU) patients included in the European observational sepsis occurrence in acutely ill patients (SOAP) study. Design: Planned substudy from the SOAP database. Setting: One hundred and ninety- eight ICUs in 24 European countries. Patients: All patients admitted to one of the participating ICUs. Patients were classified, according to their body mass index (BMI), as underweight ( \ 18.5 kg/m 2 ), normal weight (18.5–24.9 kg/m 2 ), over- weight (25–29.9 kg/m 2 ), obese (30– 39.9 kg/m 2 ), and very obese (C40 kg/ m 2 ). Measurements and results: The BMI was available in 2,878 (91%) of the 3,147 patients included in the SOAP study; 120 patients (4.2%) were underweight, 1,206 (41.9%) had a normal BMI, 1,047 (36.4%) were overweight, 424 (14.7%) were obese, and 81 (2.8%) were very obese. Obese and very obese patients more frequently developed ICU-acquired infections than patients in lower BMI catego- ries. Very obese patients showed a trend towards longer ICU [median (IQ): 4.1 (1.8–12.1) vs. 3.1 (1.7–7.2) days, P = 0.056) and hospital lengths of stay [14.3 (8.4–27.4) vs. 12.3 (5.1– 24.4), days P = 0.077] compared to those with a normal BMI. However, there were no significant differences among the groups in ICU or hospital mortality rates. In a multivariate Cox regression analysis, none of the BMI categories was associated with an increased risk of 60-day in-hospital death. Conclusion: BMI did not have a significant impact on mortality in this mixed population of ICU patients. Keywords Body mass index Á Multicentre Á Outcome Á Intensive care Á Nosocomial infection Introduction Excess body weight has long been recognised as a har- binger of disease and early death in the general population [1–6]. In addition to the psychological and social diffi- culties often faced by overweight people, obese individuals are more susceptible to medical complica- tions, including hypertension, type 2 diabetes mellitus, Intensive Care Med (2008) 34:1999–2009 DOI 10.1007/s00134-008-1243-0 ORIGINAL