Supplementary Material for: Pre-Transplant Weight Loss and Survival after Kidney Transplantation

<b><i>Background/Aims:</i></b> We examined post-transplant survival among obese kidney candidates who were temporarily designated waitlist inactive (status 7) due to their weight. <b><i>Methods:</i></b> Using OPTN/United Network for Organ Sharing data, patient and graft survival of adult status 7 recipients with a registration body mass index (BMI) ≥30 kg/m² (n = 328) were compared to all others (controls; n = 74,066). Status 7 recipients were then matched to controls to assess whether pre-transplant weight loss was associated with a survival benefit. <b><i>Results:</i></b> Median BMI at registration (38 vs. 27 kg/m², p &lt; 0.001) and transplant (36 vs. 27 kg/m², p &lt; 0.001) and reduction in BMI while waitlisted (-5.0 vs. 0.0%, p &lt; 0.001) were higher among status 7 than controls. Patient (status 7: 87.3%; control: 89.3%; p = 0.90) and graft survival (status 7: 82.9%; control: 81.6%; p = 0.75) were similar over 4 years. There was no association between status 7 and mortality (HR 0.96, 95% CI 0.59-1.57) or graft loss (HR 0.95, 95% CI 0.66-1.38) in the overall population nor between matched status 7 recipients and controls (patient survival: 86.0 vs. 87.5%, p = 0.20; graft survival: 82.6 vs. 77.2%, p = 0.61). <b><i>Conclusion:</i></b> Among obese status 7 kidney candidates previously considered too obese for transplant, patient and graft survival were comparable to the general transplant population. No difference in survival was observed with pre-transplant weight loss.

研究背景与目的：本研究针对因体重超标被临时标记为等待名单暂停状态（状态7）的肥胖肾移植候选者，探讨其移植后的生存情况。
研究方法：采用器官移植获取与移植网络（Organ Procurement and Transplantation Network, OPTN）与器官共享联合网络（United Network for Organ Sharing, UNOS）的数据集，将登记时身体质量指数（Body Mass Index, BMI）≥30 kg/m²的状态7成年肾移植受者（n=328）与其余所有受者（对照组，n=74066）的患者生存率与移植物生存率进行对比分析。随后将状态7受者与对照组进行匹配，以评估移植前体重减轻是否与生存获益存在关联。
研究结果：状态7组受者的登记时中位BMI（38 vs. 27 kg/m²，p<0.001）、移植时中位BMI（36 vs. 27 kg/m²，p<0.001）以及等待移植期间的BMI降幅（-5.0% vs. 0.0%，p<0.001）均显著高于对照组。随访4年期间，状态7组与对照组的患者生存率（87.3% vs. 89.3%；p=0.90）与移植物生存率（82.9% vs. 81.6%；p=0.75）均无显著差异。在总体研究人群中，状态7与死亡率（风险比Hazard Ratio, HR=0.96，95%置信区间Confidence Interval, CI：0.59~1.57）或移植物丢失风险（HR=0.95，95%CI：0.66~1.38）均无显著关联；在匹配后的状态7受者与对照组间，同样未观察到显著差异（患者生存率：86.0% vs. 87.5%，p=0.20；移植物生存率：82.6% vs.77.2%，p=0.61）。
研究结论：对于此前因体重超标被判定为不适宜移植的状态7型肥胖肾移植候选者，其患者生存率与移植物生存率与普通移植人群相当，且移植前体重减轻未带来生存获益的差异。