Session Time: 3:15pm-4:00pm
Presentation Time: 3:30pm-4:00pm
*Purpose: Dose-response relationship between preoperative and postoperative body mass index (BMI) and survival outcomes after liver transplantation (LT) has not been clearly defined yet.
*Methods: PubMed, Embase, Web of Science, and Cochrane databases were searched up to October 20th, 2019. We first performed pair-wise meta-analysis of optimal BMI (18.5-25 Kg/m2) versus underweight (<18.5), overweight (25-30), obesity class I (30-35), obesity class II (35-40) and obesity class III (>40) to pool the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). And dose-response analysis was used to estimate the relationship of graft- and patient-survival and BMI.
*Results: Twenty-three observational studies explored the association between preoperative BMI and survival outcomes (67981 individuals in 16 studies for patient survival and 36839 in 11 studies for graft survival), while only 1 reported postoperative BMI. In the pair-wise analysis, compared to optimal BMI, HRs of patient death in underweight, overweight, obesity I, obesity II, and obesity III were 2.13 (95%CI: 1.39-3.25, P<0.01), 0.96 (95%CI: 0.87-1.06, P=0.56), 1.06 (95%CI: 0.89-1.26, P=0.34), 1.36 (95%CI: 0.96-1.91, P=0.08), and 1.97 (95%CI: 1.19-3.28, P<0.01). Similarly, HRs of graft loss in underweight, overweight, obesity I, obesity II, and obesity III were 3.08 (95%CI: 1.47-6.44, P<0.01), 1.02 (95%CI: 0.89-1.18, P=0.43), 1.25 (95%CI: 0.85-1.84, P=0.14), 1.58 (95%CI: 1.08-2.30, P=0.03), and 2.90 (95%CI: 1.56-5.40, P<0.01). In the dose-response analysis, the non-linear model presents a U-shaped relationship between BMI and patient survival (Pnonlinearity <0.001). By reference to 17.5 kg/m2, as BMI increased, the patient death risk decreased to 0.72 (95%CI: 0.62-0.84) in 27 kg/m2 and then increased from 0.73(95%CI: 0.63-0.85) to 1.44 (95%CI: 1.09-1.90) in the 28.7-42 kg/m2 range. For graft loss, a U-shaped relationship was also observed (Pnonlinearity <0.001). By reference to 17.5 kg/m2, individuals in 26.7-28.0 kg/m2 had the least risk with HR of 0.62 (95%CI: 0.48-0.80) and increased to 1.64 (95%CI: 1.03-2.61) in the BMI of 42 kg/m2. Subgroup analysis by age, sex, sample size, and duration of follow-up presented similar results. We had no opportunity to explore the dose-response relationship between postoperative BMI and clinical outcomes for a lack of eligible studies.
*Conclusions: Preoperative underweight and severer obesity are both associated with significantly increased risk of graft loss and patient death. Overweight, especially BMI of 27-28 kg/m2, may improve the survival outcomes most efficiently. More studies should be performed to explain the relationship between postoperative BMI and clinical outcomes after liver transplantation.
To cite this abstract in AMA style:Song T. Non-Linear Relationship between Recipient BMI and Survival Outcomes after Liver Transplantation-A Dose-Response Meta-Analysis [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/non-linear-relationship-between-recipient-bmi-and-survival-outcomes-after-liver-transplantation-a-dose-response-meta-analysis/. Accessed May 7, 2021.
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