BACKGROUND: The impact of pretransplant body mass index (BMI) on long-term allograft outcomes after kidney transplantation remains controversial. The conventional approach of using Kaplan-Meier method to calculate the cumulative risk of death-censored allograft failure may overestimate the risk of failure especially when competing failure risks are present. METHOD: A retrospective cohort of adult first-time kidney transplant recipients was drawn from the Organ Procurement and Transplantation Network database (2001 to 2009). Based on World Health Organization obesity classification, BMI was categorized as: less than 18.5, 18.5 to <25, 25 to < 30, 30 to < 35, 35 to <40 and ≥40 kg/m. Both unadjusted and adjusted risk models were used to assess for risk of allograft failure in the presence of death as a competing event. RESULTS: A total of 108 654 recipients were studied. In both unadjusted and adjusted models, increasing BMI level was associated with increased risk of long-term allograft failure. In the adjusted model with BMI 18.5 to less than 25 as the reference, the subhazards ratios (SHRs) for BMI were: less than 18.5: SHR, 0.96; P = 0.41; 25 to less than 30: SHR, 1.05; P = 0.01; 30 to less than 35: SHR, 1.15; P = <0.001; 35 to less than 40: SHR, 1.21; P < 0.001; and greater than 40: SHR, 1.13; P = 0.002. CONCLUSIONS: Handling of death as a competing event demonstrates a graded, detrimental impact of increasing pretransplant BMI on the risk of graft failure after kidney transplantation in both unadjusted and adjusted models. Compared with previous studies, a lower BMI was not associated with an increased risk of graft loss in a competing risk model.
BACKGROUND: The impact of pretransplant body mass index (BMI) on long-term allograft outcomes after kidney transplantation remains controversial. The conventional approach of using Kaplan-Meier method to calculate the cumulative risk of death-censored allograft failure may overestimate the risk of failure especially when competing failure risks are present. METHOD: A retrospective cohort of adult first-time kidney transplant recipients was drawn from the Organ Procurement and Transplantation Network database (2001 to 2009). Based on World Health Organization obesity classification, BMI was categorized as: less than 18.5, 18.5 to <25, 25 to < 30, 30 to < 35, 35 to <40 and ≥40 kg/m. Both unadjusted and adjusted risk models were used to assess for risk of allograft failure in the presence of death as a competing event. RESULTS: A total of 108 654 recipients were studied. In both unadjusted and adjusted models, increasing BMI level was associated with increased risk of long-term allograft failure. In the adjusted model with BMI 18.5 to less than 25 as the reference, the subhazards ratios (SHRs) for BMI were: less than 18.5: SHR, 0.96; P = 0.41; 25 to less than 30: SHR, 1.05; P = 0.01; 30 to less than 35: SHR, 1.15; P = <0.001; 35 to less than 40: SHR, 1.21; P < 0.001; and greater than 40: SHR, 1.13; P = 0.002. CONCLUSIONS: Handling of death as a competing event demonstrates a graded, detrimental impact of increasing pretransplant BMI on the risk of graft failure after kidney transplantation in both unadjusted and adjusted models. Compared with previous studies, a lower BMI was not associated with an increased risk of graft loss in a competing risk model.
Authors: Lauren Boland; Laura Melanie Bitterlich; Andrew E Hogan; James A Ankrum; Karen English Journal: Front Immunol Date: 2022-07-04 Impact factor: 8.786
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Authors: Rajasree Menon; Edgar A Otto; Celine C Berthier; Viji Nair; Evan A Farkash; Jeffrey B Hodgin; Yingbao Yang; Jinghui Luo; Kenneth J Woodside; Haniyeh Zamani; Silas P Norman; Roger C Wiggins; Matthias Kretzler; Abhijit S Naik Journal: Kidney Int Date: 2021-12-22 Impact factor: 18.998
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