Obesity in kidney transplantation….

Dan Ridgway, Consultant Surgeon, Royal Liverpool University Hospital

Audience question.

What would be your main concern about a pre-dialysis patient with BMI of 35 having a live donor kidney transplant?

A Surgical complications (SSI)

B Risk of acute rejectionC Risk of delayed graft functionD Risk of graft loss (within 5 years)E Risk of mortality compared to dialysisF All of the above

Why worry?

• Success of transplantation• Epidemiology of obesity• Individual patient outcomes• Regulatory scrutiny• Stewardship

D. L. Segev, et al. (2008). `Obesity impacts access to kidney transplantation.'. Journal of the American Society of Nephrology : JASN 19(2):349-355.

What is the evidence?

• Low quality evidence.• Registry data.• Outcomes – perioperative complications

-short term complications (3-6 months)-medium term graft and pt survival (upto 5 years)

• BMI centric.• Wrong comparator.• Pre vs post transplant obesity.• No interventional RCTs for pre-Tx obesity.

Up to now……………

H. U. Meier-Kriesche, et al. (1999). `The effect of body mass index on long-term renal allograft survival.'. Transplantation 68(9):1294-1297.

Not simply ‘obesity’….

• More likely to be elderly• More likely to be diabetic• More likely to be from ethnic minority

background

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• Obesity (BMI) at listing has no consistent effect on DGF, AR and graft or pt survival in individual observational studies.

• Meta-analysis implies 40% increased risk of DGF.

• Slightly increased risk of AR.

• No increased risk of mortality upto 5 years under ‘new’ immunosuppression.

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S. P. Curran, et al. (2014). `Increased recipient body mass index is associated with acute rejection and other adverse outcomes after kidney transplantation.'.

Transplantation 97(1):64-70.

S. P. Curran, et al. (2014). `Increased recipient body mass index is associated with acute rejection and other adverse outcomes after kidney transplantation.'.

Transplantation 97(1):64-70.

J. D. Schold, et al. (2007). `A "weight-listing" paradox for candidates of renal transplantation?'. American Journal of Transplantation 7(3):550-559.

M. Z. Molnar, et al. (2011). `Associations of body mass index and weight loss with mortality in transplant-waitlisted maintenance hemodialysis patients.'. American Journal of

Transplantation 11(4):725-736.

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C. P. Kovesdy, et al. (2010). `Body mass index, waist circumference and mortality in kidney transplant recipients.'. American Journal of Transplantation

10(12):2644-2651.

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K. Kalantar-Zadeh, et al. (2012). `Mortality prediction by surrogates of body composition: an examination of the obesity paradox in hemodialysis patients using composite ranking score analysis.'. American Journal of Epidemiology

175(8):793-803.

J. H. Kuo, et al. (2012). `Renal transplant wound complications in the modern era of obesity.'. The Journal of Surgical Research 173(2):216-223

• BMI is a poor measure of ‘fatness’ and CV risk in CKD

• More discerning anthropometrics needed

• Avoid sarcopenic obesity

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Abdominal obesity Visceral obesity

Surgical injury

Donor factors

Immune injury

activation

Fat is immunologically active tissue

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P. M. Moraes-Vieira, et al. (2014). `Leptin deficiency impairs maturation of dendritic cells and enhances induction of regulatory T and Th17 cells.'. European

Journal of Immunology 44(3):794-806.

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J. S. Gill, et al. (2013). `The survival benefit of kidney transplantation in obese patients.'. American Journal of Transplantation 13(8):2083-2090.

J. Oberholzer, et al. (2013). `Minimally invasive robotic kidney transplantation for obese patients previously denied access to transplantation.'. American Journal of Transplantation 13(3):721-728.

Robotic (n=28) Conventional (n= 28)

BMI 42.6 38.1 P=0.02

Surgical site infection

0 8 p=0.004

6 month Cr (mg/dl)

1.5 1.6 P=0.47

6 month graft survival

28 28

6 month pt survival

28 28

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• Viseral obesity and sarcopenia is a pro-inflammatory milieu.

• Graft factors can adjust Tx risks.• SCD, ECD and LD transplants reduce

mortality at 1 year compared to equivalent wait-listed patients.

P.-T. T. Pham, et al. (2013). `Kidney transplantation in the obese transplant candidates: to transplant or not to transplant?'. Seminars in Dialysis 26(5):568-577.

Audience question.

What would be your main concern about a pre-dialysis patient with BMI of 35 having a live donor kidney transplant?

A Surgical complications (SSI)

B Risk of acute rejectionC Risk of delayed graft functionD Risk of graft loss (within 5 years)E Risk of mortality compared to dialysisF All of the above