title: The new Body Mass Index as a predictor of postoperative complications in elective colorectal cancer surgery.
abstract: OBJECTIVE
  A new Body Mass Index (BMI) formula has been developed for a better approximation of under and overweight. The aim of this study was to investigate the predictive value of this newly proposed BMI formula for postoperative complications in elective colorectal cancer surgery compared with the conventional BMI formula.
  
  
  METHODS
  A digital database of patients undergoing elective colorectal cancer surgery was prospectively maintained in three centers and retrospectively analyzed. Data consisted of patient characteristics, surgical procedure, length of hospital stay (LOS), postoperative complications, mortality, reoperation and readmission. The BMI was calculated using both the conventional and new BMI formula. Patients were divided into four groups (BMI <20, 20-25, 25-30, ≥30 kg/m(2)).
  
  
  RESULTS
  A total of 1614 patients were included. There was no significant difference in mean BMI between males and females using the conventional BMI formula (26.0 versus 26.2, p = 0.347), whereas a trend was observed using the new BMI formula (26.3 versus 25.6, p = 0.071). The proportion of overweight (BMI ≥25) male patients was significantly higher compared with the proportion of overweight female patients using the conventional formula (58.9% versus 51.0%, p = 0.021), whereas a non-significant difference was observed using the new formula (51.7% versus 53.4%, p = 0.515). Neither the conventional nor the new BMI were associated with postoperative complications and LOS. Higher age, higher ASA classification, male gender, and conventional surgery were independent predictors of the occurrence of postoperative complications. A longer LOS was also independently predicted by higher age, higher ASA classification and conventional surgery.
  
  
  CONCLUSIONS
  This study showed no superiority of the new BMI formula in predicting postoperative complications after colorectal cancer surgery. Confirmation of the results in a larger cohort is desirable.
authors.affiliation: Department of Surgery, Orbis Medical Center, Sittard-Geleen, The Netherlands; Department of Surgery, St Antonius Hospital, Nieuwegein, The Netherlands. Electronic address: j.van.vugt@antoniusziekenhuis.nl.
authors.forename: Jeroen L A
authors.initials: JL
authors.lastname: van Vugt
authors.affiliation: Department of Surgery, Orbis Medical Center, Sittard-Geleen, The Netherlands; Department of Surgery, Medical Center Alkmaar, Alkmaar, The Netherlands.
authors.forename: Hamit
authors.initials: H
authors.lastname: Cakir
authors.affiliation: Department of Surgery, St Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Verena N N
authors.initials: VN
authors.lastname: Kornmann
authors.affiliation: Trial Center Holland Health, Alkmaar, The Netherlands.
authors.forename: Hieronymus J
authors.initials: HJ
authors.lastname: Doodeman
authors.affiliation: Department of Surgery, Orbis Medical Center, Sittard-Geleen, The Netherlands.
authors.forename: Jan H M B
authors.initials: JH
authors.lastname: Stoot
authors.affiliation: Department of Surgery, St Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Djamila
authors.initials: D
authors.lastname: Boerma
authors.affiliation: Department of Surgery, Medical Center Alkmaar, Alkmaar, The Netherlands; Trial Center Holland Health, Alkmaar, The Netherlands.
authors.forename: Alexander P J
authors.initials: AP
authors.lastname: Houdijk
authors.affiliation: Department of Surgery, Orbis Medical Center, Sittard-Geleen, The Netherlands.
authors.forename: Karel W E
authors.initials: KW
authors.lastname: Hulsewé
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001835:Body Weight; D015179:Colorectal Neoplasms / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000009:adverse effects*; D017558:Elective Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000601:surgery; D050177:Overweight / Q000150:complications / Q000601:surgery; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Body Mass Index; Cancer; Colorectal surgery; Postoperative complications; Predictive value