title: Obesity--a risk factor for postoperative complications in general surgery?
abstract: BACKGROUND
  Obesity is generally believed to be a risk factor for the development of postoperative complications. Although being obese is associated with medical hazards, recent literature shows no convincing data to support this assumption. Moreover a paradox between body mass index and survival is described. This study was designed to determine influence of body mass index on postoperative complications and long-term survival after surgery.
  
  
  METHODS
  A single-centre prospective analysis of postoperative complications in 4293 patients undergoing general surgery was conducted, with a median follow-up time of 6.3 years. We analyzed the impact of bodyweight on postoperative morbidity and mortality, using univariate and multivariate regression models.
  
  
  RESULTS
  The obese had more concomitant diseases, increased risk of wound infection, greater intraoperative blood loss and a longer operation time. Being underweight was associated with a higher risk of complications, although not significant in adjusted analysis. Multivariate regression analysis demonstrated that underweight patients had worse outcome (HR 2.1; 95 % CI 1.4-3.0), whereas being overweight (HR 0.6; 95 % CI 0.5-0.8) or obese (HR 0.7; 95 % CI 0.6-0.9) was associated with improved survival.
  
  
  CONCLUSIONS
  Obesity alone is a significant risk factor for wound infection, more surgical blood loss and a longer operation time. Being obese is associated with improved long-term survival, validating the obesity paradox. We also found that complication and mortality rates are significantly worse for underweight patients. Our findings suggest that a tendency to regard obesity as a major risk factor in general surgery is not justified. It is the underweight patient who is most at risk of major postoperative complications, including long-term mortality.
authors.forename: E K M
authors.initials: EK
authors.lastname: Tjeertes
authors.affiliation: Department of anesthesiology, Erasmus University Medical Centre, Room H-1273, PO Box 2040, 3000, CA, Rotterdam, The Netherlands. e.tjeertes@erasmusmc.nl.
authors.forename: Elke E K M
authors.initials: EE
authors.lastname: Tjeertes
authors.forename: S E
authors.initials: SE
authors.lastname: Hoeks
authors.affiliation: Department of anesthesiology, Erasmus University Medical Centre, Room H-1273, PO Box 2040, 3000, CA, Rotterdam, The Netherlands.
authors.forename: Sanne S E
authors.initials: SS
authors.lastname: Hoeks
authors.forename: S B J
authors.initials: SB
authors.lastname: Beks
authors.affiliation: Department of surgery, Orbis Medical Centre, Sittard, The Netherlands.
authors.forename: Sabine S B J C
authors.initials: SS
authors.lastname: Beks
authors.forename: T M
authors.initials: TM
authors.lastname: Valentijn
authors.affiliation: Department of anesthesiology, Erasmus University Medical Centre, Room H-1273, PO Box 2040, 3000, CA, Rotterdam, The Netherlands.
authors.forename: Tabita T M
authors.initials: TT
authors.lastname: Valentijn
authors.forename: A G M
authors.initials: AG
authors.lastname: Hoofwijk
authors.affiliation: Department of surgery, Orbis Medical Centre, Sittard, The Netherlands.
authors.forename: Anton A G M
authors.initials: AA
authors.lastname: Hoofwijk
authors.affiliation: Department of anesthesiology, Erasmus University Medical Centre, Room H-1273, PO Box 2040, 3000, CA, Rotterdam, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: Stolker
authors.forename: Robert Jan R J
authors.initials: RJ
authors.lastname: Stolker
mesh_terms: D000328:Adult; D000368:Aged; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D013514:Surgical Procedures, Operative / Q000379:methods; D013534:Survival; D013851:Thinness / Q000150:complications*