The impact of obesity in renal transplantation: an analysis of paired cadaver kidneys

Abstract

Previous studies indicate that obesity is a risk factor in renal transplantation. However, these analyses did not control for variable donor factors that may strongly influence outcome. To control for donor variables such as age, cause of death, procurement techniques, preservation methods, cold ischaemia time and implantation technique, we analysed patient and graft survival in recipients of paired kidneys, derived from the same procurement procedure, preserved in the same manner, subjected to similar cold ischaemia time and implanted by the same surgical team. Between June 1992 and August 1999, 28 procurement procedures provided kidneys which were transplanted into one obese and one non-obese recipient. Body mass index (BMI) was calculated as kg/m2. Recipients were classified as obese (BMI > 30) or non-obese (BMI < 30). Immunotherapy for all recipients consisted of a triple therapy regimen of cyclosporine or prograf, azathioprine or cellcept, and prednisone. Patients with delayed graft function (DGF), defined as the need for dialysis within 72 h of the transplant procedure, were treated with anti-thymocyte globulin (ATG) or thymoglobulin (TMG) induction for 5-7 d. The rate of DGF (7.1 versus 10.7%) and acute rejection (39.3 versus 35.7%) were similar in the obese and non-obese recipient groups. Patient survival was similar at 1, 3 and 5 yr in both groups. In addition, graft survival was similar at 1 yr. However, a trend toward decreased medium-term graft survival, which reached significance at 5 yr, was observed in the obese group. Furthermore, mean serum creatinine at 1 yr was higher in the obese group (2.0) compared with the non-obese group (1, 4) (p=0.12). This analysis of paired cadaver kidneys indicated that obesity is not a risk factor for DGF, acute rejection, and 1-yr graft survival. However, a decreased medium- and long-term graft survival trend, which reached statistical significance at 5 yr, was observed in obese recipients.

Impact of obesity on urologic complications among unrelated living donor kidney transplants

“…The impact of recipient obesity on patient and graft survival is controversial; Some reports described BMI as a putative independent risk factor for patient mortality and graft failure independent of patient death after renal transplantation [19]. Some investigators have demonstrated no association between obesity and adverse graft survival, despite the increased risk among obese recipients for wound infections and DGF [12][13][14][15][16].…”

“…Urinary complications are common following renal transplantation. Some authors report that the outcomes for obese kidney transplant recipients are inferior to those of non-obese recipients [7][8][9][10][11][12][13] whereas others report no difference in outcomes [14][15][16][17]. This may be related in part to selection of the study populations, but most reports do not differentiate between obese patients (BMI between 25 and 30 kg/m 2 ) and morbidly obese patients (BMI > 35 kg/ m 2 ).…”

Paediatric obesity and renal transplantation: current challenges and solutions

“…In the adult population, there is conflicting evidence as to whether obesity is related to a higher incidence of acute rejection [19,[25][26][27][28]. The available paediatric evidence appears to suggest a similar experience, with little difference in the rate of acute rejection between obese and non-obese patients.…”

Obesity and Kidney Transplantation

“…Delayed graft function (DGF), defined as the need for dialysis therapy in the first week after kidney transplantation, places a recipient at increased risk for chronic rejection and decreased graft survival. Only a minority of single-center studies have shown that obesity increases risk for decreased graft survival after kidney transplantation (46)(47)(48)(49)(50)(51)(52)(53) but this may be due to small sample sizes in these single-center studies. In a large study which included 51,927 kidney transplant recipients, severe obesity (BMI > 35 kg/m 2 ) was associated with a 51% increased risk of DGF compared to the transplant recipients with a BMI between 22-24 kg/m 2 (41).…”

“…In transplant recipients, obesity is also associated with heightened risk of infections, and post-transplant diabetes (49)(50)(51)(52)(53). One single-center study which included 2013 adult kidney transplants performed between 1984 and 1998, superficial or deep wound infections occurred in 4.8%, whereas 3.6% developed either a fascial dehiscence or hernia of the wound (54).…”