Table 1.

Recent Findings on BMI and Other Metrics of Fat Distribution as Predictors of Transplant-Related Outcomes

Citation	Study Design and Participants	Transplant-Related Outcomes	Results/Conclusions
Lynch, R. J., et al. (2009) [51]	Retrospective cohort study 869 KT recipients at a single center between 2003 and 2008; 351 with obese BMI (>30 kg/m2)	Graft loss SSI Post-Transplant Mortality	SSI, but not obese BMI, independently associated with increase in risk of graft loss at 3 years [HR] 2.2 (95% [CI] 1.36–3.55) Risk factors for SSI: recipient age, DGF, & BMI >30 kg/m2 Obese BMI was not an independent risk factor for mortality or graft loss
Kovesdy, C. P., et al. (2010) [22]	Prospective cohort study 993 KT recipients in Budapest February and August 2007 until death or June 27, 2010	Mortality Graft Loss	Waist circumference more accurate predictor of mortality than BMI Unadjusted moratlity HRs (95%CI) associated with one SD higher BMI and waist circumference: 0.94 (0.78, 1.13), p=0.50 and 1.20 (1.00, 1.45), p=0.05, respectively Higher BMI associated with lower mortality after adjustment for waist circumference (0.48 [0.34, 0.69], p<0.001); higher waist circumference more strongly associated with higher mortality after adjustment for BMI (2.18 [1.55–3.08], p<0.001)
Luan, F. L., et al. (2010) [19]	Retrospective cohort study 591 non-diabetic KT recipients in one center between 1999 and 2005 who were followed up to 2006	NODAT Incident metabolic syndrome	314 (53.1%) had metabolic syndrome and 90 (15.2%) developed NODAT 84 patients with NODAT also had metabolic syndrome (14.2%) Risk factors for metabolic syndrome: weight gain after transplant associated with metabolic syndrome Risk factors for NODAT: Black race, old age, and HTN-related ESRD Risk factors for both: elevated BMI and fasting glucose levels at transplant
Molnar, M. Z., et al. (2011) [16]	Retrospective cohort study 14,632 KT waitlisted HD patients from 7/2001–6/2007 Used 13-week-averaged BMI & pre-TX serum creatinine as a muscle mass surrogate and their changes over time	Waiting List Mortality	Each kg/m2 increase of BMI was associated with a lower hazard of death (HR 0.96 95%CI: 0.95–0.97) Compared to the lowest serum creatinine quintile, the 4th and 5th quintiles had lower mortality HRs: 0.75 (95 % CI 0.66–0.86) and 0.57 (95% CI 0.49–0.66), respectively Compared to minimal (< +/− 1 kg) weight change over 6 months, those with 3kg – < 5kg and ≥ 5kg weight loss had mortality HRs of 1.31 (1.14–1.52) and 1.51 (1.30–1.75), respectively
Streja E. et al. (2011) [52]	Retrospective cohort study 10,090 HD patients who underwent KT between July 2001 to June 2007	Graft Loss Mortality	Relative to KT recipients with BMI 22–25 kg/m2, recipients with pre-KT BMI >35 kg/ m2 had similar post-KT mortality Higher graft loss in KT recipients with higher BMI Compared with low creatinine and low BMI groups, groups with high creatinine and high BMI had 34% lower adjusted mortality risk (HR: 0.66 [0.49 to 0.88], P < 0.01) 2.2-fold higher risk of death or graft loss with pre-KT serum creatinine <4.0 mg/dL 22% better graft and patient survival with pre-KT serum creatinine ≥14.0 mg/dL Every 1-mg/dL increase of pretransplant serum creatinine associated with 6% lower combined risk of death or graft loss when adjusted for BMI and other covariates (HR: 0.94 [0.91 to 0.97], P <0.001)
Weissenbacher, A., et al. (2012) [53]	Retrospective cohort study 1132 DDKT recipients at a single center, transplanted between 2000 and 2009	DGF, defined as requirement for dialysis within the first week after KT	Recipient BMI is an independent predictor of DGF DGF rates were 25.2%, 29.8%, 40.9%, and 52.6% in recipients with BMI <18.5, 18.5 to 24.9, 25 to 29.9, and ≥30 kg/m2, respectively (P<0.0001)
Gill et al. (2013) [54]	Retrospective cohort study National cohort (n=208,498) waitlisted on HD or transplanted between 1995 and 2007	Mortality after KT relative to remaining on HD	HD patients with an obese BMI (>30 kg/ m2) who receive KT have survival advantage compared to remaining on HD 1 year post KT survival benefit: 48% lower mortality with BMI ≥40 kg/ m2 & ≥66% lower mortality with BMI < 40 kg/m2 Survival benefit of KT relative to HD was not observed in Black race subgroup with BMI ≥ 40 kg/m2
Nicoletto, B. B., et al. (2014) [18]	Meta-analysis 21 studies (9,296 participants) included	DGF Graft Survival Mortality	Obese BMI (>30 kg/m2) was associated with DGF (RR 1.41; 95%CI: 1.26–1.57; I=8%; Pheterogeneity=0.36), but not with acute rejection Conclusion: Graft and patient survival similar between recipients with obese BMI and recipients with healthy BMI (18–25 kg/m2)
Dedinska et al, 2015 [23]	Retrospective cohort study 167 DDKT recipients in the years 2003–2012) at single center with information on waist circumference, BMI and weight gain one year after KT	NODAT Mortality Graft Loss	64 recipients developed NODAT Waist circumference, but not BMI, was independent risk factor for NODAT Higher waist circumference related to higher incidence of NODAT (r=0.1935, [95% CI: 0.01156 to 0.3630], P=0.04) Independent risk factors for NODAT: Age>50 years at time of KT (aHR=2.50, [95% CI: 1.72 to 3.65], P<0.0001) Waist circumference in men >94 cm (aHR=1.95, [95% CI: 1.17 to 3.25], P=0.01) and in women >80 cm (HR=4.50, [95% CI: 1.87 to 10.86], P=0.009
Krishnan, N., et al. (2015) [55]	Retrospective cohort study in United Kingdom including 13,526 patients on KT waitlist who were listed from Jan 1, 2004 to Dec 31, 2010, with follow-up until Dec 31, 2011	1 and 5 Year Mortality	1 and 5 year patient survival significantly better in all BMI groups (<18.5, 18.5-<25, 25-<30, 30-<35, 35-<40, and 40+ kg/m2) with KT relative to remaining on the waiting list (p < 0.0001)
Lafranca JA, et al. (2015) [56]	Retrospective cohort study Meta-analysis of 56 studies (data of more than 209,000 KT recipients)	Acute Rejection Wound Infection and Dehisence Graft Loss Mortality Transplant operation duration NODAT Transplant hospitalization LOS	High BMI (>30 kg/m2) is associated with lower post-KT mortality with an overall HR of 0.93 (CI, 0.89–0.97; P <0.001, I2 0%; P = 0.68) Relative to low BMI (<30 kg/m2) KT recipients, outcomes of recipients with high BMI (≥30 kg/m2): DGF (RR = 1.52) Acute rejection (RR = 1.17) 1-, 2-, and 3-year graft survival (RR = 0.97, 0.95, and 0.97) Wound infection and dehiscence (RR = 3.13 and 4.85) NODAT (RR = 2.24) Operation duration (+0.77 hours) LOS (+2.31 days)
Kwan, J. M., et al. (2016) [20]	Retrospective cohort atudy US Scientific Registry of Transplant Recipients database 191,091 KT recipients from 1987–2013	Post-KT proteinuria Acute rejection Graft Loss DGF	Combined data for DDKT & LDKT recipients: Recipients with obese BMI: increased risk DGF, graft loss, proteinuria and acute rejection relative to normal BMI recipients Non-diabetic recipients with a BMI between 30–34.9 kg/m2 had similar graft survival to recipients with normal BMI Subset analysis of LDKT recipients: Difference in graft loss between lower and higher BMI recipients not significantly different
Schachtner, T., et al. (2017) [21]	Retrospective cohort study 660 KT recipients at single center, received KT between 2005 and 2012	Mortality DGF Graft Loss LOS	Among recipients with obesity (BMI>30 kg/m2), only those who also had pre-existing diabetes mellitus had inferior patient and allograft survival, worse allograft function, DGF, and prolonged hospital LOS (p<0.05) compared to KT recipients without obesity No significant differences in patient or allograft survival, DGF, or hospital LOS when comparing non-diabetic KT recipients with obesity and both diabetic and non-diabetic KT recipients without obesity (p>0.05)
Erturk, T., et al. (2019) [17]	Retrospective cohort study 561 LDKT recipients from a single center in Turkey	LOS Post-TX hospital readmission rate DGF Graft Loss Mortality NODAT	Pre-KT obese BMI >30 kg/m2) associated with: Delayed wound healing (P=0.03), Longer hospitalization LOS (P=0.03) More readmissions (P =0.04), NODAT(P =0.02), and CAD (P=0.03) Increased graft loss (P=0.04) Obesity at one year post-KT associated with: Increased graft loss at years 3 & 5 post-KT (P = .04 and P = .03, respectively) Increased 5-year mortality (P = .03)
Fellmann, M., et al. (2020) [57]	Retrospective cohort study 506 HD patients who received a KT at one center over 11 year period	DGF Graft Loss Mortality	Obese BMI (≥30 kg/m2) associated with DGF: HR 2.60 [95% CI 1.31–5.02], P=0.004) & higher graft loss (HR 1.55 [1.06–2.99], P =0.04) Obese BMI not associated with increased mortality (HR = 1.82 [0.88–3.79], P=0.11)

Abbreviations: HD – hemodialysis; KT – kidney transplantation; DGF—delayed graft function; HTN – hypertension; aHR – adjusted HR; OR – odds ratio; aOR – adjusted OR; CI – confidence interval; DDKT – deceased donor KT; LDKT – living donor KT; RR – Relative risk; HR – Hazard ratio; SD – standard deviation; SSI – surgical site infection; CAD – coronary artery disease; BMI – body mass index; USRDS – United States Renal Data Service; NODAT - new onset diabetes after transplantation; LOS – length of hospital stay; DM – diabetes mellitus; CAD – coronary artery disease.