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The obesity paradox in surgical intensive care unit patients



To investigate the possible impact of obesity, as assessed by body mass index (BMI), on outcome in surgical intensive care unit (ICU) patients.


Prospectively collected data from all consecutive adult patients admitted to our ICU between January 2004 and January 2009 were analysed retrospectively. BMI was calculated using the formula: BMI = body weight/height2 (kg/m2), and patients were grouped as underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), obese (30–39.9 kg/m2) and very obese (≥40 kg/m2).


Among the 12,938 patients who were admitted to our ICU during the study period, 9,935 (76.8%) had complete height and weight data and constituted the study group. The mean BMI was 27.1 ± 5.0 kg/m2. Overall, 34.4% of the study population had normal BMI, 1.8% were underweight, 41.2% were overweight, 20.8% were obese and 1.8% were very obese. The ICU mortality rate was similar among BMI subgroups, but hospital mortality was higher in underweight patients than in patients with normal BMI (17.8% versus 11.1%, P = 0.006). On multivariate Cox regression analysis, being overweight [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.74–0.99, P = 0.047] or obese (HR = 0.83, 95% CI = 0.69–0.99, P = 0.047) was independently associated with lower 60-day in-hospital mortality, with normal BMI as the reference category. Risk of death increased in very obese patients, especially after neurosurgical procedures (HR = 0.3, 95% CI = 1.06–8.48, P = 0.039).


In this cohort of surgical ICU patients, being overweight or obese was associated with decreased risk of 60-day in-hospital mortality.

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  1. Calle EE, Thun MJ, Petrelli JM, Rodriguez C, Heath CW Jr (1999) Body–mass index and mortality in a prospective cohort of US adults. N Engl J Med 341:1097–1105

    PubMed  Article  CAS  Google Scholar 

  2. Haslam DW, James WP (2005) Obesity. Lancet 366:1197–1209

    PubMed  Article  Google Scholar 

  3. Adams KF, Schatzkin A, Harris TB, Kipnis V, Mouw T, Ballard-Barbash R, Hollenbeck A, Leitzmann MF (2006) Overweight, obesity, and mortality in a large prospective cohort of persons 50–71 years old. N Engl J Med 355:763–778

    PubMed  Article  CAS  Google Scholar 

  4. Bercault N, Boulain T, Kuteifan K, Wolf M, Runge I, Fleury JC (2004) Obesity-related excess mortality rate in an adult intensive care unit: a risk-adjusted matched cohort study. Crit Care Med 32:998–1003

    PubMed  Article  Google Scholar 

  5. Lee WY, Mokhlesi B (2008) Diagnosis and management of obesity hypoventilation syndrome in the ICU. Crit Care Clin 24:533–549 vii

    PubMed  Article  Google Scholar 

  6. Joffe A, Wood K (2007) Obesity in critical care. Curr Opin Anaesthesiol 20:113–118

    PubMed  Article  Google Scholar 

  7. El Solh A, Sikka P, Bozkanat E, Jaafar W, Davies J (2001) Morbid obesity in the medical ICU. Chest 120:1989–1997

    PubMed  Article  CAS  Google Scholar 

  8. Goulenok C, Monchi M, Chiche JD, Mira JP, Dhainaut JF, Cariou A (2004) Influence of overweight on ICU mortality: a prospective study. Chest 125:1441–1445

    PubMed  Article  Google Scholar 

  9. Brown CV, Neville AL, Rhee P, Salim A, Velmahos GC, Demetriades D (2005) The impact of obesity on the outcomes of 1,153 critically injured blunt trauma patients. J Trauma 59:1048–1051

    PubMed  Article  Google Scholar 

  10. Bochicchio GV, Joshi M, Bochicchio K, Nehman S, Tracy JK, Scalea TM (2006) Impact of obesity in the critically ill trauma patient: a prospective study. J Am Coll Surg 203:533–538

    PubMed  Article  Google Scholar 

  11. Nasraway SA Jr, Albert M, Donnelly AM, Ruthazer R, Shikora SA, Saltzman E (2006) Morbid obesity is an independent determinant of death among surgical critically ill patients. Crit Care Med 34:964–970

    PubMed  Article  Google Scholar 

  12. O’Brien JM Jr, Welsh CH, Fish RH, Ancukiewicz M, Kramer AM (2004) Excess body weight is not independently associated with outcome in mechanically ventilated patients with acute lung injury. Ann Intern Med 140:338–345

    PubMed  Google Scholar 

  13. Brown CV, Rhee P, Neville AL, Sangthong B, Salim A, Demetriades D (2006) Obesity and traumatic brain injury. J Trauma 61:572–576

    PubMed  Article  Google Scholar 

  14. Morris AE, Stapleton RD, Rubenfeld GD, Hudson LD, Caldwell E (2007) Steinberg KP (The association between body mass index and clinical outcomes in acute lung injury. Chest 131:342–348

    PubMed  Article  Google Scholar 

  15. Sakr Y, Madl C, Filipescu D, Moreno R, Groeneveld J, Artigas A, Reinhart K, Vincent JL (2008) Obesity is associated with increased morbidity but not mortality in critically ill patients. Intensive Care Med 34:1999–2009

    PubMed  Article  Google Scholar 

  16. Hogue CW Jr, Stearns JD, Colantuoni E, Robinson KA, Stierer T, Mitter N, Pronovost PJ, Needham DM (2009) The impact of obesity on outcomes after critical illness: a meta-analysis. Intensive Care Med 35:1152–1170

    PubMed  Article  Google Scholar 

  17. Oliveros H, Villamor E (2008) Obesity and mortality in critically ill adults: a systematic review and meta-analysis. Obesity (Silver Spring) 16:515–521

    Article  Google Scholar 

  18. Oreopoulos A, Padwal R, Kalantar-Zadeh K, Fonarow GC, Norris CM, McAlister FA (2008) Body mass index and mortality in heart failure: a meta-analysis. Am Heart J 156:13–22

    PubMed  Article  Google Scholar 

  19. Le Gall JR, Lemeshow S, Saulnier F (1993) A new Simplified Acute Physiology Score (SAPS II) based on a European/North American multicenter study. JAMA 270:2957–2963

    PubMed  Article  CAS  Google Scholar 

  20. Vincent JL, Moreno R, Takala J, Willatts S, de Mendonca A, Bruining H, Reinhart CK, Suter PM, Thijs LG (1996) The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. On behalf of the Working Group on Sepsis-Related Problems of the European Society of Intensive Care Medicine. Intensive Care Med 22:707–710

    PubMed  Article  CAS  Google Scholar 

  21. Vincent JL, de Mendonca A, Cantraine F, Moreno R, Takala J, Suter PM, Sprung CL, Colardyn F, Blecher S (1998) Use of the SOFA score to assess the incidence of organ dysfunction/failure in intensive care units: results of a multicenter, prospective study. Working group on “sepsis-related problems” of the European Society of Intensive Care Medicine. Crit Care Med 26:1793–1800

    PubMed  Article  CAS  Google Scholar 

  22. Miranda DR, de Rijk A, Schaufeli W (1996) Simplified Therapeutic Intervention Scoring System: the TISS-28 items–results from a multicenter study. Crit Care Med 24:64–73

    PubMed  Article  CAS  Google Scholar 

  23. Finkielman JD, Gajic O, Afessa B (2004) Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study. BMC Emerg Med 4:3

    PubMed  Article  Google Scholar 

  24. Garrouste-Orgeas M, Troché G, Azoulay E, Caubel A, de Lassence A, Cheval C, Montesino L, Thuong M, Vincent F, Cohen Y, Timsit J (2004) Body mass index. An additional prognostic factor in ICU patients. Intensive Care Med 30:437–443

    PubMed  Article  Google Scholar 

  25. O’Brien JM Jr, Phillips GS, Ali NA, Lucarelli M, Marsh CB, Lemeshow S (2006) Body mass index is independently associated with hospital mortality in mechanically ventilated adults with acute lung injury. Crit Care Med 34:738–744

    PubMed  Article  Google Scholar 

  26. Romero-Corral A, Montori VM, Somers VK, Korinek J, Thomas RJ, Allison TG, Mookadam F, Lopez-Jimenez F (2006) Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies. Lancet 368:666–678

    PubMed  Article  Google Scholar 

  27. Salahudeen AK (2006) The obesity paradox as it relates to survival and hypertension in dialysis patients. Nephrol Dial Transplant 21:1729

    PubMed  Article  Google Scholar 

  28. Wurzinger B, Dunser MW, Wohlmuth C, Deutinger MC, Ulmer H, Torgersen C, Schmittinger CA, Grander W, Hasibeder WR (2010) The association between body–mass index and patient outcome in septic shock: a retrospective cohort study. Wien Klin Wochenschr 122:31–36

    PubMed  Article  Google Scholar 

  29. Druml W, Metnitz B, Schaden E, Bauer P, Metnitz PG (2010) Impact of body mass on incidence and prognosis of acute kidney injury requiring renal replacement therapy. Intensive Care Med 36:1221–1228

    PubMed  Article  Google Scholar 

  30. Tremblay A, Bandi V (2003) Impact of body mass index on outcomes following critical care. Chest 123:1202–1207

    PubMed  Article  Google Scholar 

  31. Rose DK, Cohen MM, Wigglesworth DF, DeBoer DP (1994) Critical respiratory events in the postanesthesia care unit. Patient, surgical, and anesthetic factors. Anesthesiology 81:410–418

    PubMed  Article  CAS  Google Scholar 

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Supported by an unrestricted grant of the Ministry of Culture Thuringia (Landesprogramm ProExzellenz; PE 108-2), the Foundation of Technology, Innovation and Research Thuringia (STIFT) and the German Sepsis Society (GSS).

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Correspondence to Yasser Sakr.

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Hutagalung, R., Marques, J., Kobylka, K. et al. The obesity paradox in surgical intensive care unit patients. Intensive Care Med 37, 1793 (2011).

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  • Perioperative
  • Obesity
  • Prognosis