- Email: [email protected]
Renal Transplantation in Obese Patients: Experience in an Argentine Center
Renal Transplantation in Obese Patients: Experience in an Argentine Center F. Mosa, J. Robertib,*, N. Fascea, M. Paza, and F. Cicoraa,b a Renal Transplant, Hospital Alemán (German Hospital) of Buenos Aires, Buenos Aires, Argentina; and bFoundation for Research and Assistance of Renal Disease (Finaer), Argentina
ABSTRACT Possible complications of renal transplants in obese patients have raised concerns among nephrologists. We describe the outcomes of 110 renal transplant patients according to body mass index (BMI). Recipient BMI was calculated by using height and weight at time of transplantation and categorized according to World Health Organization guidelines. The patients’ BMI values were as follows: underweight, n ¼ 8 (7.27%); normal weight, n ¼ 55 (50%); overweight, n ¼ 30 (27.27%); and obese, n ¼ 17 (15.45%). Mean age was significantly different among groups: underweight, 27.62 7.57 years; normal weight, 44.98 15.55 years; overweight, 50.53 13.90 years; and obese, 52.11 10.41 years (P < .05). Donor age and mean time of dialysis treatment were comparable in all groups. Underweight patients had a significantly larger proportion of living donors than those with higher BMIs. Calculated glomerular filtration rate (using the Modification of Diet in Renal Disease equation) were significantly different among the groups at 30, 60, and 90 days’ posttransplantation. At 180 days, however, it was comparable: underweight, 62.96 40.77 mL/min/1.73 m2; normal weight, 53.55 26.23 mL/min/1.73 m2; overweight, 47.52 16.37 mL/min/1.73 m2; and obese, 46.19 17.56 mL/min/1.73 m2 (P ¼ .34). Incidence of delayed graft function was as follows: underweight, 0%; normal weight, 30.4%; overweight, 53.3%; and obese, 64.1% (P < .05). The incidence of surgical complications, incidence of rejection within the first 6 months’ posttransplantation, and graft and patient survival rates over 6 months did not differ among the groups. Because transplantation in obese patients may be associated with higher risks and costs, the evaluation of each center experience is imperative. Longer term assessments are warranted, but our short-term results show that outcomes in overweight or obese renal transplant patients are comparable to those in patients with lower BMI.
K
IDNEY transplantation is the best treatment for patients with end-stage renal disease, offering better survival rates and quality of life than dialysis [1]. As the incidence of obesity, defined as a body mass index (BMI) >30 kg/m2, has increased dramatically in the general population, so has the proportion of renal transplant recipients categorized as overweight or obese [2]. Obesity is associated with reduced mortality during dialysis [3,4], but large studies indicate that despite this relatively improved prognosis, renal transplantation offers longer life expectancy for obese patients with end-stage renal disease [5,6]. Possible complications of renal transplants in obese patients have raised concerns among nephrologists [7]; thus, even merely descriptive studies could help guide treatment decisions. Whether a patient is a candidate for transplantation
depends on the treatment center’s experience, results, costs, and risk tolerance [8]. Because , to the best of our knowledge, no local studies on obese renal transplant recipients have yet been published, we herein describe the outcomes of 110 renal transplant patients according to their BMI. PATIENTS AND METHODS We included patients aged >18 years who underwent kidney transplantation from January 1, 2011, through January 31, 2013. Recipient BMI was calculated by using height and weight at time of
*Address correspondence to Javier Roberti, LPsy, PhD(c), Austria 2381, 5D, 1425 Buenos Aires, Argentina. E-mail: [email protected]
ª 2014 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/14 http://dx.doi.org/10.1016/j.transproceed.2014.07.004
Transplantation Proceedings, 46, 2981e2983 (2014)
2981
2982
MOS, ROBERTI, FASCE ET AL
transplantation and categorized according to World Health Organization guidelines as follows: underweight, BMI <18.5 kg/m2; normal, 18.5 to 24.9 kg/m2; overweight, 25 to 29.9 kg/m2; and obese, 30 kg/m2. No dietary initiatives were applied to patients, and none of the patients underwent a gastric banding procedure. Outcomes included the incidence of delayed graft function (DGF), defined as dialysis requirement in the first week after transplantation, and graft and patient survival, rejection episodes, and calculated glomerular filtration rate (using the Modification of Diet in Renal Disease equation) over the first 6 months. Surgical complications were classified by using the Clavien-Dindo score, a morbidity scale based on the therapeutic consequences of complications [9]. Data were compared among groups by using the c2 test, the Fisher exact test, and analysis of variance as appropriate. BMI was assessed as both a continuous and a categorical variable (obese vs nonobese). Multivariate analysis of categorical variables was performed by using logistic regression, and graft survival was compared by using the log rank test. Data were analyzed with the use of Stata version 11 (StataCorp, College Station, Tex, United States). A value of P <.05 was taken to indicate statistical significance.
RESULTS
BMI values from the 110 study patients were distributed as follows: underweight, n ¼ 8 (7.27%); normal weight, n ¼ 55 (50%); overweight, n ¼ 30 (27.27%); and obese, n ¼ 17 (15.45%). Mean age was significantly different among groups: underweight, 27.62 7.57 years; normal weight, 44.98 15.55 years; overweight, 50.53 13.90 years; and obese, 52.11 10.41 years (P < .05). Donor age, time of dialysis treatment, cold ischemia time (CIT), and number of mismatches were comparable in all groups. Underweight patients had a significantly larger proportion of living donors than those with larger BMIs. Table 1 displays patient characteristics. Calculated glomerular filtration rates were significantly different among groups at 30, 60, and 90 days’ posttransplantation (Table 2). However, the mean calculated glomerular filtration rate at 180 days was comparable in the 4 groups: underweight, 62.96 40.77 mL/min/1.73 m2; normal weight, 53.55 26.23 mL/min/1.73 m2; overweight, 47.52 16.37 mL/min/1.73 m2; and obese, 46.19 17.56 mL/min/ 1.73 m2 (P ¼ .34). DGF incidence varied significantly: underweight, 0%; normal weight, 30.91%; overweight, 53.33%; and obese, 64.71% (P < .05). The incidence of rejection
within the first 6 months’ posttransplantation did not vary significantly. Although mean CIT was comparable in all BMI groups, when comparing mean CIT in the group of patients who had DGF versus the group without DGF, a significant difference was observed: 1117.11 79.83 minutes versus 672.45 79.47 minutes, respectively (P < .05). The incidence of surgical complications did not differ among the groups. The most common types of surgical complications were 1 and 3B, as per the Clavien-Dindo score, occurring in 27.9% and 14.4%, respectively, and a mean score of 0.85 1.19 for all patients. Logistic regression analysis identified increasing BMI (odds ratio, 1.30 [95% confidence interval, 1.13e1.51]; P < .001), increasing recipients’ age, and receiving an organ from a deceased donor as independent prognostic factors for DGF. Over 6 months, graft and patient survival rates were comparable in all groups (Table 2). DISCUSSION
Obese patients are more likely than other patients to have cardiovascular disease, the main cause of death in renal transplant recipients, as well as other comorbidities that may affect transplant outcomes (eg, posttransplant diabetes mellitus, dyslipidemia, hypertension) [10]. Several studies have demonstrated a benefit from transplantation in obese patients [6,11e13]. A BMI >30 kg/m2 has been identified as the main risk factor for surgical complications, longer hospital stays, early graft loss, and DGF [10]. Although high BMI at transplant does not affect survival rates per se, it does seem to increase DGF rates [2,7,12,13]. Coincidentally, we found significantly higher rates of DGF in overweight and obese patients than in normal or underweight patients, but the incidence of other outcomes, including surgical complications, was comparable. Although mean ischemia time was not statistically different in BMI groups, it was significantly higher in those patients who presented with DGF, which is in line with the literature showing that an increasing CIT is associated with a higher incidence of DGF (although not necessarily with deleterious consequences in the long term) [14]. At our center, no dietary initiatives are applied before or after transplant; however, overweight and obese patients are encouraged to consult with a dietitian, modify their diet, and, if possible, become physically active.
Table 1. Baseline Characteristics of Patients Grouped According to BMI Characteristic
Group 1 (n ¼ 8) underweight, BMI <18.5 kg/m2
Group 2 (n ¼ 55) normal, BMI 18.5 to 24.9 kg/m2
Group 3 (n ¼ 30) overweight, BMI 25 to 29.9 kg/m2
Group 4 (n ¼ 17) obese, 30 kg/m2
P Value
BMI Male Age, y LD DD Dialysis, mo CIT, min Mismatches
17.22 0.38 1 (12.5) 27.6 7.57 6 (75) 2 (25) 47.5 35.01 284.12 372.17 3.62 1.41
22.14 1.76 36 (64.25) 44.98 15.55 18 (32.73) 37 (67.27) 59.47 52.46 866.05 652.11 2.93 1.52
27.29 1.27 21 (7) 50.53 13.90 9 (30) 21 (70) 41.0 28.38 923.23 577 2.77 1.48
32.95 3.02 11 (6.47) 52.11 10.41 5 (29.4) 12 (70.6) 55.67 40.58 937.18 621.61 2.82 1.59
<.05 <.05 <.05 NS NS NS NS NS
Data are expressed as mean values SDs or number (%). Abbreviations: BMI, body mass index; CIT, cold ischemia time; ; DD, deceased donor; LD, living donor; NS, not significant.
RENAL TRANSPLANTS IN OBESE PATIENTS
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Table 2. Outcomes of Patients Grouped According to BMI Outcome
DGF, no. (%) AR 6 mo, no. (%) Graft survival, % Patient survival, % cGFR, mL/min/1.73 m2, mean SD Baseline 1 mo 3 mo 6 mo Surgical complications, no. (%)
Group 1 underweight, BMI <18.5 kg/m2
Group 2 normal, BMI 18.5 to 24.9 kg/m2
Group 3 overweight, BMI 25 to 29.9 kg/m2
Group 4 obese, BMI 30 kg/m2
P Value
0 0 100 100
17 (30.91) 14 (25) 98 93
16 (53.33) 3 (10) 96.7 90
11 (64.71) 3 (17.6) 94.1 86
<.05 NS NS NS
8.93 3.91 52.23 21.54 51.84 21.44 53.55 26.23 23 (41)
6.61 2.69 38.53 21.48 47.92 17.17 47.52 16.37 15 (50)
7.62 94.99 77.39 62.96 4
2.95 31.30 26.60 40.77 (50)
7.59 46.53 49.19 46.19 9
3.70 20.26 18.31 17.56 (52)
<.05 <.05 <.05 NS NS
Abbreviations: AR, acute rejection; BMI, body mass index; cGFR, calculated glomerular filtration rate (using the Modification of Diet in Renal Disease equation); DGF, delayed graft function.
Prospective studies on weight loss and bariatric surgery are needed to establish guidelines for improving outcomes and access to transplantation in obese patients [3,8]. Weight loss before transplantation does not affect survival after transplantation, and such loss is transitory [4,15]. In addition, requiring that patients lose weight before transplantation could be unrealistic and prolong waiting time [13]. Selecting donors associated with better outcomes may be more sensible; Gill et al [6] observed that most obese patients survive longer after transplants from any donor source, although the benefit is lower in patients with a BMI >40 kg/m2 and uncertain in black patients, and highlighted the use of living donors as a strategy to improve outcomes. Although this study’s observational nature, small sample size, and short follow-up time limit the degree to which its conclusions can be assumed representative, it was warranted to explore outcomes in our population and health system, which are different from those described in the literature. Nonetheless, measures other than BMI, such as waist circumference or waist-to-hip ratio, may be better indicators of abdominal obesity [7,8,10,16]. In conclusion, because transplantation in obese or morbidly obese patients may be associated with higher risks and costs [8], evaluation of each center’s experience is imperative. Longer term assessments are necessary, but our study revealed that, in the short term, outcomes in overweight or obese renal transplant patients are comparable to those in patients with lower BMI. REFERENCES [1] Port FK, Wolfe R, Mauger E, et al. Comparison of survival probabilities for dialysis patients vs cadaveric renal transplant recipients. JAMA 1993;270:1339e43.
[2] Gore JL, Pham PT, Danovitch GM, et al. Obesity and outcome following renal transplantation. Am J Transplant 2006;6: 357e63. [3] Friedman AN. Obesity in patients undergoing dialysis and kidney transplantation. Adv Chronic Kidney Dis 2013;20:128e34. [4] Schold JD, Srinivas TR, Guerra G, et al. A “weight-listing” paradox for candidates of renal transplantation? Am J Transplant 2007;7:550e9. [5] Tonelli M, Wiebe N, Knoll G, et al. Systematic review: kidney transplantation compared with dialysis in clinically relevant outcomes. Am J Transplant 2011;11:2093e109. [6] Gill JS, Lan J, Dong J, et al. The survival benefit of kidney transplantation in obese patients. Am J Transplant 2013:2083e90. [7] Chang SH, Coates PT, McDonald SP. Effects of body mass index at transplant on outcomes of kidney transplantation. Transplantation 2007;84:981e7. [8] Lentine KL, Delos Santos R, Axelrod D, et al. Obesity and kidney transplant candidates: how big is too big for transplantation? Am J Nephrol 2012;36:575e86. [9] Dindo D, Demartines N, Clavien PA. Classification of surgical complications. Ann Surg 2004;240:205e13. [10] Heinbokel T, Floerchinger B, Schmiderer A, et al. Obesity and its impact on transplantation and alloimmunity. Transplantation 2013;96:10e6. [11] Rao PS, Schaubel DE, Wei G, et al. Evaluating the survival benefit of kidney retransplantation. Transplantation 2006;82: 669e74. [12] Gurkan A, Kacar S, Varilsuha C. Renal transplantation in obese patients. Saudi J Kidney Dis Transpl 2013;24:795e7. [13] Marks WH, Florence LS, Chapman PH, et al. Morbid obesity is not a contraindication to kidney transplantation. Am J Surg 2004;187:635e8. [14] Legendre C, Canaud G, Martinez F. Delayed kidney graft function: from mechanism to translation. Transpl Int 2014;27:19e27. [15] Molnar MZ, Streja E, Kovesdy CP, et al. Associations of body mass index and weight loss with mortality in transplantwaitlisted maintenance hemodialysis patients. Am J Transplant 2011;11:725e36. [16] Kovesdy CP, Czira ME, Rudas A, et al. Body mass index, waist circumference and mortality in kidney transplant recipients. Am J Transplant 2010;10:2644e51.
ABSTRACT Possible complications of renal transplants in obese patients have raised concerns among nephrologists. We describe the outcomes of 110 renal transplant patients according to body mass index (BMI). Recipient BMI was calculated by using height and weight at time of transplantation and categorized according to World Health Organization guidelines. The patients’ BMI values were as follows: underweight, n ¼ 8 (7.27%); normal weight, n ¼ 55 (50%); overweight, n ¼ 30 (27.27%); and obese, n ¼ 17 (15.45%). Mean age was significantly different among groups: underweight, 27.62 7.57 years; normal weight, 44.98 15.55 years; overweight, 50.53 13.90 years; and obese, 52.11 10.41 years (P < .05). Donor age and mean time of dialysis treatment were comparable in all groups. Underweight patients had a significantly larger proportion of living donors than those with higher BMIs. Calculated glomerular filtration rate (using the Modification of Diet in Renal Disease equation) were significantly different among the groups at 30, 60, and 90 days’ posttransplantation. At 180 days, however, it was comparable: underweight, 62.96 40.77 mL/min/1.73 m2; normal weight, 53.55 26.23 mL/min/1.73 m2; overweight, 47.52 16.37 mL/min/1.73 m2; and obese, 46.19 17.56 mL/min/1.73 m2 (P ¼ .34). Incidence of delayed graft function was as follows: underweight, 0%; normal weight, 30.4%; overweight, 53.3%; and obese, 64.1% (P < .05). The incidence of surgical complications, incidence of rejection within the first 6 months’ posttransplantation, and graft and patient survival rates over 6 months did not differ among the groups. Because transplantation in obese patients may be associated with higher risks and costs, the evaluation of each center experience is imperative. Longer term assessments are warranted, but our short-term results show that outcomes in overweight or obese renal transplant patients are comparable to those in patients with lower BMI.
K
IDNEY transplantation is the best treatment for patients with end-stage renal disease, offering better survival rates and quality of life than dialysis [1]. As the incidence of obesity, defined as a body mass index (BMI) >30 kg/m2, has increased dramatically in the general population, so has the proportion of renal transplant recipients categorized as overweight or obese [2]. Obesity is associated with reduced mortality during dialysis [3,4], but large studies indicate that despite this relatively improved prognosis, renal transplantation offers longer life expectancy for obese patients with end-stage renal disease [5,6]. Possible complications of renal transplants in obese patients have raised concerns among nephrologists [7]; thus, even merely descriptive studies could help guide treatment decisions. Whether a patient is a candidate for transplantation
depends on the treatment center’s experience, results, costs, and risk tolerance [8]. Because , to the best of our knowledge, no local studies on obese renal transplant recipients have yet been published, we herein describe the outcomes of 110 renal transplant patients according to their BMI. PATIENTS AND METHODS We included patients aged >18 years who underwent kidney transplantation from January 1, 2011, through January 31, 2013. Recipient BMI was calculated by using height and weight at time of
*Address correspondence to Javier Roberti, LPsy, PhD(c), Austria 2381, 5D, 1425 Buenos Aires, Argentina. E-mail: [email protected]
ª 2014 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/14 http://dx.doi.org/10.1016/j.transproceed.2014.07.004
Transplantation Proceedings, 46, 2981e2983 (2014)
2981
2982
MOS, ROBERTI, FASCE ET AL
transplantation and categorized according to World Health Organization guidelines as follows: underweight, BMI <18.5 kg/m2; normal, 18.5 to 24.9 kg/m2; overweight, 25 to 29.9 kg/m2; and obese, 30 kg/m2. No dietary initiatives were applied to patients, and none of the patients underwent a gastric banding procedure. Outcomes included the incidence of delayed graft function (DGF), defined as dialysis requirement in the first week after transplantation, and graft and patient survival, rejection episodes, and calculated glomerular filtration rate (using the Modification of Diet in Renal Disease equation) over the first 6 months. Surgical complications were classified by using the Clavien-Dindo score, a morbidity scale based on the therapeutic consequences of complications [9]. Data were compared among groups by using the c2 test, the Fisher exact test, and analysis of variance as appropriate. BMI was assessed as both a continuous and a categorical variable (obese vs nonobese). Multivariate analysis of categorical variables was performed by using logistic regression, and graft survival was compared by using the log rank test. Data were analyzed with the use of Stata version 11 (StataCorp, College Station, Tex, United States). A value of P <.05 was taken to indicate statistical significance.
RESULTS
BMI values from the 110 study patients were distributed as follows: underweight, n ¼ 8 (7.27%); normal weight, n ¼ 55 (50%); overweight, n ¼ 30 (27.27%); and obese, n ¼ 17 (15.45%). Mean age was significantly different among groups: underweight, 27.62 7.57 years; normal weight, 44.98 15.55 years; overweight, 50.53 13.90 years; and obese, 52.11 10.41 years (P < .05). Donor age, time of dialysis treatment, cold ischemia time (CIT), and number of mismatches were comparable in all groups. Underweight patients had a significantly larger proportion of living donors than those with larger BMIs. Table 1 displays patient characteristics. Calculated glomerular filtration rates were significantly different among groups at 30, 60, and 90 days’ posttransplantation (Table 2). However, the mean calculated glomerular filtration rate at 180 days was comparable in the 4 groups: underweight, 62.96 40.77 mL/min/1.73 m2; normal weight, 53.55 26.23 mL/min/1.73 m2; overweight, 47.52 16.37 mL/min/1.73 m2; and obese, 46.19 17.56 mL/min/ 1.73 m2 (P ¼ .34). DGF incidence varied significantly: underweight, 0%; normal weight, 30.91%; overweight, 53.33%; and obese, 64.71% (P < .05). The incidence of rejection
within the first 6 months’ posttransplantation did not vary significantly. Although mean CIT was comparable in all BMI groups, when comparing mean CIT in the group of patients who had DGF versus the group without DGF, a significant difference was observed: 1117.11 79.83 minutes versus 672.45 79.47 minutes, respectively (P < .05). The incidence of surgical complications did not differ among the groups. The most common types of surgical complications were 1 and 3B, as per the Clavien-Dindo score, occurring in 27.9% and 14.4%, respectively, and a mean score of 0.85 1.19 for all patients. Logistic regression analysis identified increasing BMI (odds ratio, 1.30 [95% confidence interval, 1.13e1.51]; P < .001), increasing recipients’ age, and receiving an organ from a deceased donor as independent prognostic factors for DGF. Over 6 months, graft and patient survival rates were comparable in all groups (Table 2). DISCUSSION
Obese patients are more likely than other patients to have cardiovascular disease, the main cause of death in renal transplant recipients, as well as other comorbidities that may affect transplant outcomes (eg, posttransplant diabetes mellitus, dyslipidemia, hypertension) [10]. Several studies have demonstrated a benefit from transplantation in obese patients [6,11e13]. A BMI >30 kg/m2 has been identified as the main risk factor for surgical complications, longer hospital stays, early graft loss, and DGF [10]. Although high BMI at transplant does not affect survival rates per se, it does seem to increase DGF rates [2,7,12,13]. Coincidentally, we found significantly higher rates of DGF in overweight and obese patients than in normal or underweight patients, but the incidence of other outcomes, including surgical complications, was comparable. Although mean ischemia time was not statistically different in BMI groups, it was significantly higher in those patients who presented with DGF, which is in line with the literature showing that an increasing CIT is associated with a higher incidence of DGF (although not necessarily with deleterious consequences in the long term) [14]. At our center, no dietary initiatives are applied before or after transplant; however, overweight and obese patients are encouraged to consult with a dietitian, modify their diet, and, if possible, become physically active.
Table 1. Baseline Characteristics of Patients Grouped According to BMI Characteristic
Group 1 (n ¼ 8) underweight, BMI <18.5 kg/m2
Group 2 (n ¼ 55) normal, BMI 18.5 to 24.9 kg/m2
Group 3 (n ¼ 30) overweight, BMI 25 to 29.9 kg/m2
Group 4 (n ¼ 17) obese, 30 kg/m2
P Value
BMI Male Age, y LD DD Dialysis, mo CIT, min Mismatches
17.22 0.38 1 (12.5) 27.6 7.57 6 (75) 2 (25) 47.5 35.01 284.12 372.17 3.62 1.41
22.14 1.76 36 (64.25) 44.98 15.55 18 (32.73) 37 (67.27) 59.47 52.46 866.05 652.11 2.93 1.52
27.29 1.27 21 (7) 50.53 13.90 9 (30) 21 (70) 41.0 28.38 923.23 577 2.77 1.48
32.95 3.02 11 (6.47) 52.11 10.41 5 (29.4) 12 (70.6) 55.67 40.58 937.18 621.61 2.82 1.59
<.05 <.05 <.05 NS NS NS NS NS
Data are expressed as mean values SDs or number (%). Abbreviations: BMI, body mass index; CIT, cold ischemia time; ; DD, deceased donor; LD, living donor; NS, not significant.
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Table 2. Outcomes of Patients Grouped According to BMI Outcome
DGF, no. (%) AR 6 mo, no. (%) Graft survival, % Patient survival, % cGFR, mL/min/1.73 m2, mean SD Baseline 1 mo 3 mo 6 mo Surgical complications, no. (%)
Group 1 underweight, BMI <18.5 kg/m2
Group 2 normal, BMI 18.5 to 24.9 kg/m2
Group 3 overweight, BMI 25 to 29.9 kg/m2
Group 4 obese, BMI 30 kg/m2
P Value
0 0 100 100
17 (30.91) 14 (25) 98 93
16 (53.33) 3 (10) 96.7 90
11 (64.71) 3 (17.6) 94.1 86
<.05 NS NS NS
8.93 3.91 52.23 21.54 51.84 21.44 53.55 26.23 23 (41)
6.61 2.69 38.53 21.48 47.92 17.17 47.52 16.37 15 (50)
7.62 94.99 77.39 62.96 4
2.95 31.30 26.60 40.77 (50)
7.59 46.53 49.19 46.19 9
3.70 20.26 18.31 17.56 (52)
<.05 <.05 <.05 NS NS
Abbreviations: AR, acute rejection; BMI, body mass index; cGFR, calculated glomerular filtration rate (using the Modification of Diet in Renal Disease equation); DGF, delayed graft function.
Prospective studies on weight loss and bariatric surgery are needed to establish guidelines for improving outcomes and access to transplantation in obese patients [3,8]. Weight loss before transplantation does not affect survival after transplantation, and such loss is transitory [4,15]. In addition, requiring that patients lose weight before transplantation could be unrealistic and prolong waiting time [13]. Selecting donors associated with better outcomes may be more sensible; Gill et al [6] observed that most obese patients survive longer after transplants from any donor source, although the benefit is lower in patients with a BMI >40 kg/m2 and uncertain in black patients, and highlighted the use of living donors as a strategy to improve outcomes. Although this study’s observational nature, small sample size, and short follow-up time limit the degree to which its conclusions can be assumed representative, it was warranted to explore outcomes in our population and health system, which are different from those described in the literature. Nonetheless, measures other than BMI, such as waist circumference or waist-to-hip ratio, may be better indicators of abdominal obesity [7,8,10,16]. In conclusion, because transplantation in obese or morbidly obese patients may be associated with higher risks and costs [8], evaluation of each center’s experience is imperative. Longer term assessments are necessary, but our study revealed that, in the short term, outcomes in overweight or obese renal transplant patients are comparable to those in patients with lower BMI. REFERENCES [1] Port FK, Wolfe R, Mauger E, et al. Comparison of survival probabilities for dialysis patients vs cadaveric renal transplant recipients. JAMA 1993;270:1339e43.
[2] Gore JL, Pham PT, Danovitch GM, et al. Obesity and outcome following renal transplantation. Am J Transplant 2006;6: 357e63. [3] Friedman AN. Obesity in patients undergoing dialysis and kidney transplantation. Adv Chronic Kidney Dis 2013;20:128e34. [4] Schold JD, Srinivas TR, Guerra G, et al. A “weight-listing” paradox for candidates of renal transplantation? Am J Transplant 2007;7:550e9. [5] Tonelli M, Wiebe N, Knoll G, et al. Systematic review: kidney transplantation compared with dialysis in clinically relevant outcomes. Am J Transplant 2011;11:2093e109. [6] Gill JS, Lan J, Dong J, et al. The survival benefit of kidney transplantation in obese patients. Am J Transplant 2013:2083e90. [7] Chang SH, Coates PT, McDonald SP. Effects of body mass index at transplant on outcomes of kidney transplantation. Transplantation 2007;84:981e7. [8] Lentine KL, Delos Santos R, Axelrod D, et al. Obesity and kidney transplant candidates: how big is too big for transplantation? Am J Nephrol 2012;36:575e86. [9] Dindo D, Demartines N, Clavien PA. Classification of surgical complications. Ann Surg 2004;240:205e13. [10] Heinbokel T, Floerchinger B, Schmiderer A, et al. Obesity and its impact on transplantation and alloimmunity. Transplantation 2013;96:10e6. [11] Rao PS, Schaubel DE, Wei G, et al. Evaluating the survival benefit of kidney retransplantation. Transplantation 2006;82: 669e74. [12] Gurkan A, Kacar S, Varilsuha C. Renal transplantation in obese patients. Saudi J Kidney Dis Transpl 2013;24:795e7. [13] Marks WH, Florence LS, Chapman PH, et al. Morbid obesity is not a contraindication to kidney transplantation. Am J Surg 2004;187:635e8. [14] Legendre C, Canaud G, Martinez F. Delayed kidney graft function: from mechanism to translation. Transpl Int 2014;27:19e27. [15] Molnar MZ, Streja E, Kovesdy CP, et al. Associations of body mass index and weight loss with mortality in transplantwaitlisted maintenance hemodialysis patients. Am J Transplant 2011;11:725e36. [16] Kovesdy CP, Czira ME, Rudas A, et al. Body mass index, waist circumference and mortality in kidney transplant recipients. Am J Transplant 2010;10:2644e51.