title: The new body mass index system in predicting renal graft outcomes.
abstract: BACKGROUND
  Obesity has been related to poor renal graft function. The aim of this study was to compare the long-term graft outcomes of living-related kidney recipients regarding donor-to-recipient body mass index (BMI) parameters using the old Quetelet BMI formula and the new Trefethen BMI formula.
  
  
  METHODS
  From November 2002 to November 2010, 62 consecutive living-related kidney transplantations were reviewed retrospectively. Four donor-to-recipient BMI parameters were used: (1) BMI difference by the old formula, (2) BMI difference by the new formula, (3) BMI ratio by the old formula, and (4) BMI ratio by the new formula. Long-term outcomes, including graft survival (GS) and rejection-free graft survival (RFGS) either overall or at 5 years post-transplantation, were analysed according to these parameters.
  
  
  RESULTS
  The baseline demography was similar among tertiles according to the four BMI parameters tested. Although there is no significant difference in the long-term survivals by the old and new BMI formula, we found that the area under receiver operating characteristic (ROC) curve is larger using the new formula, either by BMI difference (0.584 vs 0.559 in 5-year GS and 0.658 vs 0.636 in 5-year RFGS) or by BMI ratio (0.584 vs 0.561 in 5-year GS and 0.644 vs 0.626 in 5-year RFGS). The same trend was observed in overall survival outcomes.
  
  
  CONCLUSIONS
  The new Trefethen BMI formula seems to predict long-term renal graft outcomes better than the old Quetelet BMI formula.
authors.affiliation: Department of Urology, Chang Gung University, Taoyuan, Taiwan; Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Transplantation Institute, Taoyuan, Taiwan. Electronic address: seanwang@cgmh.org.tw.
authors.forename: H-H
authors.initials: HH
authors.lastname: Wang
authors.affiliation: Department of Urology, Chang Gung University, Taoyuan, Taiwan; Chang Gung Transplantation Institute, Taoyuan, Taiwan.
authors.forename: K-J
authors.initials: KJ
authors.lastname: Lin
authors.affiliation: Department of Urology, Chang Gung University, Taoyuan, Taiwan; Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Transplantation Institute, Taoyuan, Taiwan.
authors.forename: S-H
authors.initials: SH
authors.lastname: Chu
authors.affiliation: Department of Urology, Chang Gung University, Taoyuan, Taiwan; Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Transplantation Institute, Taoyuan, Taiwan.
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Chiang
authors.affiliation: Department of Urology, Chang Gung University, Taoyuan, Taiwan; Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Transplantation Institute, Taoyuan, Taiwan.
authors.forename: K-L
authors.initials: KL
authors.lastname: Liu
authors.affiliation: Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Transplantation Institute, Taoyuan, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Hsieh
mesh_terms: D015992:Body Mass Index; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D016030:Kidney Transplantation; D014019:Tissue Donors