The impact of donor body mass index on outcomes after deceased kidney transplantation - a national population-cohort study.

The aim of this study was to determine the effect of donor body mass index (BMI) on deceased donor kidney transplant outcomes. Data were collected from the UK Transplant Registry for all deceased donor kidney transplant recipients between January 2003 and January 2015. Univariable and multivariable analyses were undertaken to assess the impact of donor BMI on a range of outcomes. Donor BMI (kg/m2 ) was stratified as <18.5 (n = 380), 18.5-25.0 (n = 6890), 25.1-30.0 (n = 6669), 30.1-35.0 (n = 2503) and >35.0 (n = 1148). The prevalence of delayed graft function increased significantly with donor BMI (P < 0.001), with an adjusted odds ratio of 1.38 (95% CI: 1.16-1.63) for the >35.0 vs. 18.5-25.0 groups. However, there was no significant association between donor BMI and 12-month creatinine (P = 0.550), or patient (P = 0.109) or graft (P = 0.590) survival. In overweight patients, increasing donor BMI was associated with a significant increase in warm ischaemia time and functional warm ischaemia time, by an average of 4.6% (P = 0.043) and 5.2% (P = 0.013) per 10.0 kg/m2 . However, rising warm ischaemic time and functional warm ischaemic time was not significantly associated with delayed graft function, 12-month creatinine levels, graft loss or patient death. In this population cohort study, we identified no significant association between donor BMI and long-term clinical outcomes in deceased donor kidney transplantation.