Obesity as a risk factor after combined pancreas/kidney transplantation

Comparable kidney transplant outcomes in selected patients with a body mass index ≥ 40: A personalized medicine approach to recipient selection

INTRODUCTION

Many kidney transplant (KT) centers decline patients with a body mass index (BMI) ≥40 kg/m2 . This study's aim was to evaluate KT outcomes according to recipient BMI.

METHODS

We performed a single-center, retrospective review of adult KTs comparing BMI ≥40 patients (n = 84, BMI = 42 ± 2 kg/m2 ) to a matched BMI < 40 cohort (n = 84, BMI = 28 ± 5 kg/m2 ). Patients were matched for age, gender, race, diabetes, and donor type.

RESULTS

BMI ≥40 patients were on dialysis longer (5.2 ± 3.2 years vs. 4.1 ± 3.5 years, p = .03) and received lower kidney donor profile index (KDPI) kidneys (40 ± 25% vs. 53 ± 26%, p = .003). There were no significant differences in prevalence of delayed graft function, reoperations, readmissions, wound complications, patient survival, or renal function at 1 year. Long-term graft survival was higher for BMI ≥40 patients, including after adjusting for KDPI (BMI ≥40: aHR = 1.79, 95% CI = 1.09-2.9). BMI ≥40 patients had similar BMI change in the first year post-transplant (delta BMI: BMI ≥ 40 +.9 ± 3.3 vs. BMI < 40 +1.1 ± 3.2, p = .59).

CONCLUSIONS

Overall outcomes after KT were comparable in BMI ≥40 patients compared to a matched cohort with lower BMI with improved long-term graft survival in obese patients. BMI-based exclusion criteria for KT should be reexamined in favor of a more individualized approach.

Modern indications for referral for kidney and pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation (PTx) is currently the only therapy that can predictably achieve sustained euglycemia independent of exogenous insulin administration in patients with insulin-dependent diabetes mellitus. This procedure involves a complex abdominal operation and lifetime dependence on immunosuppressive medications. Therefore, PTx is most frequently performed in combination with other organs, usually a kidney transplant for end stage diabetic nephropathy. Less frequently, solitary PTx may be indicated in patients with potentially life-threatening complications of diabetes mellitus. There remains confusion and misperceptions regarding indications and timing of patient referral for PTx.

RECENT FINDINGS

In this review, the referral, evaluation, and listing process for PTx is described, including a detailed discussion of candidate assessment, indications, contraindications, and outcomes.

SUMMARY

Because the progression of diabetic kidney disease may be less predictable than other forms of kidney failure, early referral for planning of renal and/or pancreas transplantation is paramount to optimize patient care and allow for possible preemptive transplantation.

Pancreas Transplantation in Minorities including Patients with a Type 2 Diabetes Phenotype

Background: Prior to year 2000, the majority of pancreas transplants (PTx) were performed as simultaneous pancreas-kidney transplants (SPKTs) in Caucasian adults with end stage renal failure secondary to type 1 diabetes mellitus (T1DM) who were middle-aged. In the new millennium, improving outcomes have led to expanded recipient selection that includes patients with a type 2 diabetes mellitus (T2DM) phenotype, which excessively affects minority populations. Methods: Using PubMed® to identify appropriate citations, we performed a literature review of PTx in minorities and in patients with a T2DM phenotype. Results: Mid-term outcomes with SPKT in patients with uremia and circulating C-peptide levels (T2DMphenotype) are comparable to those patients with T1DM although there may exist a selection bias in the former group. Excellent outcomes with SPKT suggests that the pathophysiology of T2DM is heterogeneous with elements consisting of both insulin deficiency and resistance related to beta-cell failure. As a result, increasing endogenous insulin (Cp) production following PTx may lead to freedom checking blood sugars or taking insulin, better metabolic counter-regulation, and improvements in quality of life and life expectancy compared to other available treatment options. Experience with solitary PTx for T2DM or in minorities is limited but largely mirrors the trends reported in SPKT. Conclusions: PTx is a viable treatment option in patients with pancreas endocrine failure who are selected appropriately regardless of diabetes type or recipient race. This review will summarize data that unconventional patient populations with insulin-requiring diabetes may gain value from PTx with an emphasis on contemporary experiences and appropriate selection in minorities in the new millennium.

Weight gain following pancreas transplantation in type 1 diabetes is associated with a worse glycemic profile: A retrospective cohort study

AIMS

Evaluate the weight trajectories after pancreas transplantation (PT) and their relationships with pancreas graft outcomes in type 1 diabetes (T1D).

METHODS

Retrospective cohort study. T1D individuals who underwent PT were recruited (T1D-PT; n = 194) and divided into three groups according to transplantation date: 1999-2004 (n = 57), 2005-2009 (n = 79), 2010-2015 (n = 58). For weight comparisons, a random sample of T1D without renal impairment was also recruited during 2015 (n = 61; T1D-control).

RESULTS

The median follow-up for the T1D-PT group was 11.1 years. Despite significant weight loss at 6 months (65.7 ± 12.4 vs. 64.1 ± 11.4 Kg; p < 0.001), a stepped increase was seen thereafter (60 months: 68.0 ± 14.0 Kg; p < 0.001). Participants from the 2010-2015 period showed higher weight gain (p < 0.001), outweighing that observed in the T1D-control (60 months: +4.69 ± 8.49 vs. -0.97 ± 4.59 Kg; p = 0.003). Weight gain between 6 and 36 months was directly associated with fasting glucose and HbA1c at 36 months, and with HbA1c at 60 months (p < 0.05). However, in Cox-regression models adjusted for age, sex, and several recipient and PT-related variables, the third tertile of weight gain between 6 and 36 months showed a non-significant increase in the graft failure/dysfunction (HR 2.33 [0.75-7.27]).

CONCLUSIONS

Weight gain post-PT was associated with glucose-related biochemical markers of graft dysfunction, which needs confirmation in further studies.

First World Consensus Conference on pancreas transplantation: Part II - recommendations

The First World Consensus Conference on Pancreas Transplantation provided 49 jury deliberations regarding the impact of pancreas transplantation on the treatment of diabetic patients, and 110 experts' recommendations for the practice of pancreas transplantation. The main message from this consensus conference is that both simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone can improve long-term patient survival, and all types of pancreas transplantation dramatically improve the quality of life of recipients. Pancreas transplantation may also improve the course of chronic complications of diabetes, depending on their severity. Therefore, the advantages of pancreas transplantation appear to clearly surpass potential disadvantages. Pancreas after kidney transplantation increases the risk of mortality only in the early period after transplantation, but is associated with improved life expectancy thereafter. Additionally, preemptive SPK, when compared to SPK performed in patients undergoing dialysis, appears to be associated with improved outcomes. Time on dialysis has negative prognostic implications in SPK recipients. Increased long-term survival, improvement in the course of diabetic complications, and amelioration of quality of life justify preferential allocation of kidney grafts to SPK recipients. Audience discussions and live voting are available online at the following URL address: http://mediaeventi.unipi.it/category/1st-world-consensus-conference-of-pancreas-transplantation/246.

Preoperative C-Peptide Predicts Weight Gain After Pancreas Transplantation

BACKGROUND

Transplant recipients are susceptible to cardiovascular complications, obesity, and increased insulin resistance after transplant. Here we assess weight gain in diabetic recipients after pancreas transplantation.

METHODS

This is a single-center study of 32 simultaneous pancreas and kidney and 5 pancreas after kidney transplant recipients from 2014 to 2018. Starting C-peptide levels ≤ 0.1 ng/mL were used to denote insulin nondetectability (n = 25) and C-peptide levels > 0.1 ng/mL as insulin detectability (n = 12). Hemoglobin A_1c, body mass index (BMI), and weight following transplantation were assessed.

RESULTS

Hemoglobin A_1c at 1 year was 5.9% in the insulin nondetectable recipients and 5.6% in the insulin detectable group (P = .56). Average BMI after transplant was higher in the insulin detectable group 28.6 versus 24.4 kg/m² (P = .03) despite no difference in starting BMIs (24.9 versus 24.0 kg/m², P = .42). The insulin detectable group also had a larger percentage weight change from their starting weight 13.1% versus 0.9 % at 1 year (P = .02). Linear regression demonstrated that starting C-peptide was a significant predictor of weight gain posttransplant.

CONCLUSIONS

Patients with elevated C-peptides at time of transplant are susceptible to rapid weight gain postoperatively. These patients may benefit from aggressive nutritional management.

Posttransplant Outcome of Lean Compared With Obese Nonalcoholic Steatohepatitis in the United States: The Obesity Paradox

Morbid obesity is considered a relative contraindication for liver transplantation (LT). We investigated if body mass index (BMI; lean versus obese) is a risk factor for post-LT graft and overall survival in nonalcoholic steatohepatitis (NASH) and non-NASH patients. Using the United Network for Organ Sharing (UNOS) database, LT recipients from January 2002 to June 2013 (age ≥18 years) with follow-up until 2017 were included. The association of BMI categories calculated at LT with graft and overall survival after LT were examined. After adjusting for confounders, all obesity cohorts (overweight and class 1, class 2, and class 3 obesity) among LT recipients for NASH had significantly reduced risk of graft and patient loss at 10 years of follow-up compared with the lean BMI cohort. In contrast, the non-NASH group of LT recipients had no increased risk for graft and patient loss for overweight, class 1, and class 2 obesity groups but had significantly increased risk for graft (P < 0.001) and patient loss (P = 0.005) in the class 3 obesity group. In this retrospective analysis of the UNOS database, adult recipients selected for first LT and NASH patients with the lowest BMI have the worse longterm graft and patient survival as opposed to non-NASH patients where the survival was worse with higher BMI.

Pancreas grafts for transplantation from donors with hypertension: an analysis of the scientific registry of transplant recipients database

BACKGROUND

With the rising demands for pancreas transplantation, surgeons are trying to extend the donors pool and set up a more appropriate assessment system. We aim to evaluate the effect of donor hypertension on recipient overall and graft survival rates.

METHODS

Twenty-four thousand one hundred ninety-two pancreas transplantation patients from the Scientific Registry of Transplant Recipients database were subdivided into hypertension group (HTN, n = 1531) and non-hypertension group (non-HTN, n = 22,661) according to the hypertension status of donors. Recipient overall and graft survival were analyzed and compared by log rank test, and hazard ratios of predictors were estimated using Cox proportional hazard models.

RESULTS

Patient overall and graft survival of non-HTN group were higher than that of the HTN group (both p < 0.001). The duration of hypertension negatively influenced both overall and graft survival rates (both p < 0.001). Multivariate analyses demonstrated that hypertension was an independent factor for reduced survival (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.01-1.18; p < 0.001). Other independent factors included recipient body mass index (HR, 1.02; 95% CI, 1.01-1.05; p < 0.001) and transplant type (pancreas after kidney transplants / pancreas transplant alone vs. simultaneous pancreas-kidney transplants; HR, 1.41; 95% CI, 134-1.55; p < 0.001).

CONCLUSIONS

Donor hypertension is an independent factor for recipient survival after pancreas transplantation and could be considered in donor selection as well as post-transplant surveillance in clinical practice.

Type 1 diabetic patients have better endothelial function after simultaneous pancreas-kidney transplantation than after kidney transplantation with continued insulin therapy

The purpose of this study was to analyse the influence of simultaneous pancreas-kidney or kidney transplantation on endothelial function and systemic inflammation in type 1 diabetic patients with end-stage renal disease. In 39 simultaneous pancreas-kidney, 39 type 1 diabetic kidney and 52 non-diabetic kidney recipients, flow-mediated dilatation was measured. Additionally, blood glycated haemoglobin, serum creatinine and lipids, plasma nitrites [Formula: see text] and nitrates, asymmetric dimethylarginine, soluble vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin, high-sensitivity C-reactive protein, tumour necrosis factor-α, interleukin 1β and interleukin 6 concentrations were assessed. During 58 ± 31 months follow-up period, flow-mediated dilatation and [Formula: see text] were greater in simultaneous pancreas-kidney than in type 1 diabetic kidney recipients [10.4% ± 4.7% vs 7.7% ± 4.2%, p < 0.05 and 0.94 (0.74-1.34) vs 0.24 (0.20-0.43) μmol/L, p < 0.01, respectively]. In type 1 diabetic patients after simultaneous pancreas-kidney or kidney transplantation, [Formula: see text] correlated with flow-mediated dilatation (r = 0.306, p < 0.05) and with blood glycated haemoglobin (r = -0.570, p < 0.001). The difference in [Formula: see text] was linked to blood glycated haemoglobin and estimated glomerular filtration rate, whereas the difference in flow-mediated dilatation was linked to [Formula: see text]. The levels of inflammatory markers (except soluble vascular cell adhesion molecule-1) were similar in simultaneous pancreas-kidney and type 1 diabetic kidney recipients. Improved endothelial function in type 1 diabetic patients with end-stage renal disease after simultaneous pancreas-kidney compared to kidney transplantation is associated with normalisation of glucose metabolism but not with improvement in plasma pro-inflammatory cytokines.

Pancreas Transplantation in the Modern Era

The field of pancreas transplantation has evolved from an experimental procedure in the 1980s to become a routine transplant in the modern era. With short- and long-term outcomes continuing to improve and the significant mortality, quality-of-life, and end-organ disease benefits, pancreas transplantation should be offered to more patients. In this article, we review current indications, patient selection, surgical considerations, complications, and outcomes in the modern era of pancreas transplantation.

The significance of pre-operative coronary interventions on outcome after pancreas transplantation

Pancreas transplant candidates are at very high risk of coronary vascular disease. We hypothesized that the requirement for pre-operative coronary intervention (PCI) may be associated with an adverse impact on short- and long-term outcomes. Retrospective analysis of 366 consecutive primary pancreas transplants was undertaken. Outcomes were compared between recipients who had undergone PCI (n = 48) and those who had not (n = 318). In 48% (23/48) of instances, the PCI was initiated by the transplant cardiology evaluation. The recipients undergoing PCI were older than those not undergoing PCI (47.6 yr vs. 41.9 yr, respectively, p < 0.0001). Although not statistically significant, there was a higher rate of post-operative major cardiovascular events (MCVE) in the PCI group (10.4%) compared with those not undergoing PCI (4.7%) (RR [95% CI]: 2.0 [0.90-4.5]; p = 0.17). In the long term, there were no differences in the rate of death with graft function (p = 0.77) or rejection (p = 0.17). There were no statistically significant differences between the groups with respect to patient (p = 0.54), kidney (p = 0.76), or pancreas (p = 0.63) graft survival. PCI is not a risk factor for short-term perioperative events, and long-term transplant outcomes are equivalent to patients not requiring PCI. PCI, by itself, should not be considered a contraindication for pancreas transplantation, but should raise awareness of perioperative risk.

Impact of recipient body mass index on short-term and long-term survival of pancreatic grafts

BACKGROUND

The impact of recipient body mass index on graft and patient survival after pancreas transplantation is not well known.

METHODS

We have analyzed data from all pancreas transplant recipients reported in the Scientific Registry of Transplant Recipients between 1987 and 2011. Recipients were categorized into BMI classes, as defined by the World Health Organization. Short-term (90 days) and long-term (90 days to 5 years) patient and graft survivals were analyzed according to recipient BMI class using Kaplan-Meier estimates. Hazard ratios were estimated using Cox proportional hazard models.

RESULTS

A total of 21,075 adult recipients were included in the analysis. Mean follow-up was 5 ± 1.1 years. Subjects were overweight or obese in 39%. Increasing recipient BMI was an independent predictor of pancreatic graft loss and patient death in the short term (P<0.001), especially for obese class II patient survival (hazard ratio, 2.07; P=0.009). In the long term, obesity, but not overweight, was associated with higher risk of graft failure (P=0.01). Underweight was associated with a higher risk of long-term death (P<0.001).

CONCLUSION

These results question the safety of pancreas transplantation in obese patients and suggest that they may be directed to alternate therapies, such as behavioral modifications or bariatric surgery, before pancreas transplantation is considered.

Long-Term Impact of Different Immunosuppressive Drugs on QT and PR Intervals in Renal Transplant Patients

BACKGROUND

Sudden cardiac deaths due to arrhythmias are thought to be an important cause of mortality in patients with renal transplants. Exposure to immunosuppressive drugs may lead to QT or PR interval abnormalities which may consequently cause arrhythmias. Our study investigated the long term impact of four different immunosuppressive drugs on PR and corrected QT intervals (QTc) in renal transplant patients

METHODS

The study population consisted of 98 kidney transplant recipients. Study patients were receiving immunosuppressive management with tacrolimus, cyclosporine A, everolimus or azathioprine according to the local protocols. QTc and PR intervals obtained from the most recent post-transplant electrocardiograms were compared with the pre-transplant intervals dated before the transplantation procedure.

RESULTS

Post-transplant QTc intervals had prolonged significantly in comparison to the pre-transplant QTc intervals in all groups. However, there were no significant differences between the immunosuppressive agents with regard to post-transplant QTc interval prolongation (p > 0.05). There were no significant differences between the groups with regard to the pre and post-transplant PR interval changes (p > 0.05).

CONCLUSIONS

QT interval prolongation, a marker of risk for arrhythmias and sudden death, is highly prevalent among kidney transplant patients receiving different classes of immunosuppressive drugs.

Obesity and organ transplantation: successes, failures, and opportunities

The increasing rate of societal obesity is also affecting the transplant world through obesity in candidates and donors as well as its posttransplant repercussions. Being overweight and obese has been shown to have significant effects on both short- and long-term complications as well as patient and graft survival. However, much of the comorbidity can be controlled or prevented with careful patient selection and aggressive management. A team approach to managing obesity and its comorbidities both pre- and posttransplant is essential for successful transplant outcomes. Complicating understanding the results of obesity research is the inclusion different weight categories, use of listing vs transplant weights, patient populations large enough for statistical power, and changes in transplant management, especially immunosuppression protocols, anti-infection protocols, and operative techniques. Much more research is needed regarding many elements, including safe weight loss before transplantation, prevention of weight gain after transplant, genomic influences, and the role of bariatric surgery in the transplant process.

Pancreas transplantation after bariatric surgery

Obese transplant candidates are at increased risk for perioperative and postoperative complications. In many transplant programs, morbid obesity is considered to be an exclusion criterion for transplantation. The only potential option that would grant these patients access to transplant is weight loss. Non-operative weight loss strategies such as behavioral modifications, exercise, diet, or medication have only very limited success in achieving long-term weight loss. In contrast, bariatric surgery was shown to achieve not only more excessive weight loss, but more importantly, this weight loss can be sustained for longer periods of time. Therefore, bariatric surgery presents an attractive option for weight loss for morbidly obese transplant candidates. We report our experience with four patients who underwent bariatric surgery prior to successful pancreas transplantation. Even though gastric bypass and laparoscopic adjustable gastric band present as equivalent alternatives for weight reduction, we believe that in the population of morbidly obese diabetic patients who are possible candidates for pancreas transplantation, laparoscopic adjustable gastric band placement is the more suitable procedure.

Pancreas transplantation considering the spectrum of body mass indices

BACKGROUND

In kidney, liver, heart, and lung transplantation, extremes of body mass index (BMI) have been reported to influence post-operative outcomes and even survival. Given the limited data in pancreas transplantation, we sought to elucidate the influence of BMI on outcomes.

METHODS

We reviewed 139 consecutive pancreas transplants performed at our institution and divided them into four categories based on BMI: underweight (≤18.5 kg/m(2)), normal (18.6-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), and obese (≥30 kg/m(2)). Parameters analyzed included post-operative complications, early graft loss, one-yr acute rejection rate (AR), non-surgical infections, and survival.

RESULTS

Demographic data were similar between the groups. Compared with normal, only obese patients trended toward more post-operative complications (p = 0.06). Underweight and obese patients had significantly more post-operative infectious complications than normal (p = 0.0005 and p = 0.03, respectively). Obese patients had more complications requiring percutaneous drainage compared with normal (p = 0.03). Overweight and obese patients had significantly more complications requiring re-laparotomy (p = 0.03 and p = 0.048, respectively). Early graft loss, AR, non-surgical infections, and patient and graft survival rates were not different between normal and underweight, overweight, or obese patients (p > 0.05).

CONCLUSIONS

Extremes of BMI were associated with increased morbidity. Donors and recipients should be carefully selected to maximize potential for successful outcomes.

Obesity was associated with inferior outcomes in simultaneous pancreas kidney transplant

BACKGROUND.: In kidney transplant, obesity was reported to be associated with increased posttransplant complications and worse survival outcomes. The impact of obesity in simultaneous pancreas-kidney (SPK) transplant is less known. METHODS.: Using Organ Procurement Transplantation Network/United Network for Organ Sharing data as of August 2008, we included all adults (>18 years) type 1 diabetic SPK recipients between years 2000 and 2007 with a pretransplant body mass index (BMI) of 18.5 to 40 kg/m. The cohort was divided in three groups: normal (BMI 18.5-24.9 kg/m, reference group), overweight (BMI 25-29.9 kg/m), and obese (BMI 30-40 kg/m). Covariate-adjusted relative risk of a combination of posttransplant complications and patient, pancreas and kidney allograft outcomes were evaluated. RESULTS.: Of 5725 recipients, 56%, 33%, and 11% were in normal, overweight, and obese groups, respectively. Overweight and obese recipients were older, had a higher percent of coronary artery disease, and private health insurance coverage. Overall posttransplant complications were higher in obese group (35.7% vs. 28.6%) when compared with normal BMI group. They were mainly due to increased delayed kidney graft function (11.8% vs. 7.4%), 1-year kidney acute rejection (17.0% vs. 12.1%), and pancreas graft thrombosis (2.6% vs. 1.3%). After adjusting for possible confounders, the odds ratios for overall transplant complications were 1.03 (95% confidence interval [CI]: 0.90-1.17) for overweight and 1.38 (95% CI: 1.15-1.68) for obese. Obesity, but not overweight, was associated with patient death (hazard ratio [HR]: 1.35; 95% CI: 1.00-1.81), pancreas graft loss (HR: 1.41; 95% CI: 1.17-1.69), and kidney graft loss (HR: 1.33; 95% CI: 1.05-1.67) at 3 years. The higher rates of death and graft failure in the first 30 days posttransplant mostly accounted for the 3-year survival differences. CONCLUSION.: Obesity in SPK recipients was associated with increased risk of posttransplant complications, pancreas and kidney graft loss, and patient death.

Liver transplantation at the extremes of the body mass index

Controversies exist regarding the morbidity and mortality of patients undergoing liver transplantation at the extremes of the body mass index (BMI). A review of the United Network for Organ Sharing database from 1987 through 2007 revealed 73,538 adult liver transplants. Patients were stratified into 6 BMI categories established by the World Health Organization: underweight, <18.5 kg/m(2); normal weight, 18.5 to <25 kg/m(2); overweight, 25 to <30 kg/m(2); obese, 30 to <35 kg/m(2); severely obese, 35 to <40 kg/m(2); and very severely obese, > or =40 kg/m(2). Survival rates were compared among these 6 categories via Kaplan-Meier survival curves with the log-rank test. The underweight and very severely obese groups had significantly lower survival. There were 1827 patients in the underweight group, 1447 patients in the very severely obese group, and 68,172 patients in the other groups, which became the control. Groups with extreme BMI (<18.5 and > or =40) were compared to the control to assess significant differences. Underweight patients were more likely to die from hemorrhagic complications (P < 0.002) and cerebrovascular accidents (P < 0.04). When compared with the control, the very severely obese patients had a higher number of infectious complications and cancer events (P = 0.02) leading to death. In 3 different eras of liver transplantation, multivariable analysis showed that underweight and very severe obesity were significant predictors of death. In conclusion, liver transplantation holds increased risk for patients at the extremes of BMI. Identifying these patients and instituting aggressive new policies may improve outcomes. Liver Transpl 15:968-977, 2009. (c) 2009 AASLD.

Laparoscopic gastric banding in a kidney-pancreas transplant recipient with new onset type II diabetes mellitus associated with morbid obesity

Combined kidney-pancreas transplantation is the treatment of choice for end-stage diabetic nephropathy. Post-transplant weight gain increases the risk for post-transplant complications and death owing to cardiovascular events. Gastric banding is an established treatment for moderate morbid obesity. We report on a patient who experienced significant weight gain and developed type II diabetes mellitus following successful kidney-pancreas transplantation. He underwent laparoscopic gastric banding and initially had good weight loss. However, lack of compliance with dietary guidelines led to transient failure of weight loss therapy. With further adjustment of the gastric band good weight loss was achieved.

Pretransplant obesity: a weighty issue affecting transplant candidacy and outcomes

Because of the global increase in prevalence of obesity, many more overweight and obese individuals are undergoing evaluation for transplantation than in the past. Although obesity seems to provide a survival benefit in dialysis patients, obesity has traditionally been considered a contraindication for transplantation of most organs. It is theorized that obesity will contribute to worse transplant outcomes, including lower rates of graft and patient survival and higher rates of delayed graft function and infection. This review evaluates the available literature evaluating outcomes of obese patients with end-stage organ failure who undergo transplantation. Obesity seems to be associated with increased rates of wound infection after transplantation. However, other adverse transplant outcomes related to obesity seem to be dependent on the type of organ being transplanted and the degree of obesity. For example, a body mass index (BMI) of 30 kg/m(2) may reduce short-term survival in lung transplant recipients; however, obesity does not seem to confer an adverse effect on short- or long-term survival in liver transplant patients until a much higher BMI is reached (such as 35 or 40 kg/m(2)). Each transplant center must determine weight guidelines and criteria for identifying the level of obesity as a contraindication for transplantation. This must be based on organ type, each center's transplant and complication statistics, and available donor pools. Guidelines must also consider the morbidity and mortality risks of the obese patient with organ failure who does not receive a transplant.

Laparoscopically Implanted Gastric Pacemaker after Kidney-Pancreas Transplantation: Treatment of Morbid Obesity and Diabetic Gastroparesis

Combined kidney-pancreas transplantation is the treatment of choice for end-stage diabetic nephropathy. Weight gain post-transplant increases the risk for post-transplant complications and death due to cardiovascular events. Gastric pacemakers have been used for therapy of diabetic gastropathy and for the treatment of moderate morbid obesity. We report a patient who experienced significant weight gain following successful kidney-pancreas transplantation and was thereafter successfully treated for diabetic gastroparesis and morbid obesity by use of a laparoscopically implanted gastric pacemaker.

The impact of overweight on the development of diabetes after heart transplantation

BACKGROUND

Overweight is defined with a body mass index (BMI) >25. A BMI >25 is known as an independent risk factor for increased morbidity and mortality. The influence of an increased BMI on the development of diabetes and on survival after heart transplantation (HTX) was investigated.

METHODS

A total of 137 patients (116 men, 21 women), who underwent HTX at our Department from 1986 to 2002, were included in the study. For group stratification, the pre-operative BMI values were taken (group I: BMI </or=25; group II: BMI > 25). Groups were compared for primary disease, age and sex, development of renal failure, development of diabetes, and survival. The probability of survival and the freedom-from-diabetes interval were calculated by the use of Kaplan-Meier method.

RESULTS

No significant differences between groups I and II were found concerning primary disease, age and sex, and occurrence of renal failure. There was a tendency towards increased survival (p = 0.18) in group I. Patients of group II developed diabetes after HTX more frequently than those of group I (p < 0.001). Cox regression revealed that pre-operative BMI >25 is a highly significant independent risk factor for post-operative development of diabetes mellitus (DM) (p < 0.001).

CONCLUSION

Overweight prior to HTX appears to negatively influence long-term survival after HTX, although this difference did not reach statistical significance. Pre-operative overweight is a significant and independent risk factor for the development of post-transplant diabetes.

Discordant utility of ideal body weight and body mass index as predictors of mortality in lung transplant recipients

BACKGROUND

An upper limit of 130% predicted ideal body weight (PIBW) has been promulgated for assessing lung transplant (LTx) candidacy, but no data in the lung transplant population support this value. A prior study used body mass index (BMI) to suggest greater mortality risk in obese allograft recipients, but the number of studied patients was small.

METHODS

Pre-operative PIBW percentage and BMI were obtained for all first-time, adult LTx recipients at our institution (n = 283). We compared survival data at 90 days and as of July 31, 2002, using multivariable regression and Cox modeling.

RESULTS

There were 46 obese (BMI > or = 30) patients and 72 patients >130% PIBW, including 43 patients previously thought to fall within a normal PIBW range who were reclassified as overweight for this analysis. Cox modeling revealed no significant impact of PIBW (>130% or continuous) or BMI (>30 kg/m(2) or continuous) on overall survival. Predicted ideal body weight also had no influence on 90-day mortality. When we tested PIBW in the group previously deemed of acceptable weight, we likewise found no association with mortality at 90 days or overall. For BMI only, 90-day odds ratios for death were significantly greater for obese (BMI > or = 30; odds ratio, 3.16; 95% confidence interval, 1.05-9.48) patients than for normal-weight patients.

CONCLUSION

Indices of pre-operative obesity did not predict long-term outcome in this large cohort of LTx recipients. The data suggest that BMI stratification may identify a group of patients at risk for increased short-term mortality, whereas PIBW is not a significant outcome predictor.

Cyclosporine levels at 2 hours after dose and body mass index in relation to graft function in renal transplant patients treated with azathioprine or mycophenolate mofetil

The aim of this study was to evaluate the effect of C(2) levels on renal graft function in relation to body mass index (BMI). This retrospective study of 95 renal transplant patients included 53 on AZA and 42 on MMF at 3.1 years after transplantation. The cohort was divided into groups according to their C(2) levels, namely <600 ng/mL, 600 to 900 ng/mL, or >900 ng/mL, and according to BMI (>26 kg/m(2)). In every group, we evaluated the percentage of patients with an increase in creatinine by 1 mg/dL or >/=50% from the first year posttransplant. There was no difference in age, gender, graft source, and dose of corticosteroids or CsA between the groups. Patients on AZA with C(2) 600 to 900 ng/mL showed a lower prevalence of renal dysfunction (3.4%) than those with C(2) levels <600 ng/mL (14.3%) or >900 ng/mL (20%). Seventeen percent of the patients on AZA and 11.9% on MMF had BMI >26 kg/m(2) (P = NS). An increased serum creatinine was present in 22.2% of patients with BMI >26 kg/m(2) in the AZA group vs 20% in the cohort MMF (P = NS). These findings suggest that long-standing renal recipients on AZA with C(2) levels of between 600 and 900 ng/mL show better preservation of renal function. We did not identify differences on the basis of C(2) levels in MMF-treated recipients. The influence of BMI on long-term graft function seemed to be independent of AZA or MMF therapy.

Influence of Overweight on ICU Mortality

STUDY OBJECTIVE

Overweight patients seem to have a poorer outcome and a higher risk of complications during their stay in the ICU. We conducted a prospective study in order to examine the relationship between body mass index (BMI) and mortality among these patients.

DESIGN

Prospective clinical study.

SETTING

A 24-bed medical ICU in a university-affiliated hospital.

METHODS

All patients hospitalized in the ICU over a 1-year period were included except those dying or being discharged from the hospital within 24 h of admission. Overweight patients were defined as those having a BMI > 75th percentile of this selected ICU population. Other data collected were demographic and ICU-related data. The Mann-Whitney test was used to compare numeric data between groups (ie, obese and nonobese populations). Variables that were significantly associated with ICU mortality by univariate analysis were entered into a multiple logistic regression model, allowing the determination of independent predictors.

RESULTS

Eight hundred thirteen patients were included in the study. The limit of the upper quartile of the BMI was 27. This value was used to separate obese (n = 215) and nonobese (n = 598) groups. Significant differences between obese and nonobese patients were observed in age, length of stay in the ICU, simplified acute physiology score (SAPS) II, and ICU mortality. The observed mortality of obese patients was significantly higher than that predicted by SAPS II (32% vs 18%, respectively; p = 0.001). No difference was observed in frequency of nosocomial infection or duration of mechanical ventilation for mortality in ICU patients. Using a multivariate analysis, the predictive factors of mortality were SAPS II (p < 0.0001) and BMI > 27 (p < 0.01).

CONCLUSION

This is the first prospective study showing high BMI value as an independent prognostic factor of mortality for ICU patients. The prognostic scoring systems currently in use, which were designed to predict the mortality of ICU patients, do not include BMI or do not consider obesity. These may underestimate, therefore, the risk for the specific population of obese patients.

Nutritional Assessment and Support of Kidney Transplant Recipients

Kidney transplant has become a viable option for patients with end-stage renal disease (ESRD). The number of kidney transplants has steadily increased during the past 50 years. Advances in surgical technique and immunosuppressive drugs have led to significant improvements in survival rates. Many chronic diseases that lead to ESRD negatively affect nutritional status. To minimize nutritional depletion and optimize nutritional status, a complete and thorough evaluation by a registered dietitian should be performed. The posttransplant nutritional goal is to provide adequate nutrition to promote wound healing and anabolism, to prevent infection, and to minimize side effects of medications. Providing adequate nutrition and reducing the long-term side effects are essential for graft survival in kidney transplant recipients

Impact of body weight on long-term survival after lung transplantation

STUDY OBJECTIVES

The purpose of this study was to determine the impact of a pretransplantation determination of body mass index (BMI) on survival after lung transplantation.

DESIGN AND PATIENTS

Univariate and multivariate survival analyses of a single institution database consisting of 85 patients who had undergone lung transplantations between March 1994 and October 1998.

SETTING

University of Florida Health Science Center.

RESULTS

Kaplan-Meier survival curves showed that patients who were obese (ie, BMI, > or = 30) at a pretransplantation assessment had a marked decrease in posttransplantation survival time (log rank, p < 0.05; Wilcoxon, p < 0.05). The final Cox regression model revealed that the most powerful predictors of mortality after lung transplantation were higher pretransplantation BMI and the development of obliterative bronchiolitis.

CONCLUSIONS

Our results suggest that the posttransplantation risk for mortality is possibly three times greater for obese patients than for nonobese patients. Additional study is needed to identify the mechanisms for such higher risk in obese patients. Our data also suggest that transplantation centers should not routinely reject underweight patients (ie, BMI, < 18.5) or overweight patients (ie, BMI, 25 to 29.9) for lung transplantation listing solely on the basis of weight, as their outcomes may not be significantly different than patients with normal BMIs.

Pretransplant cachexia and morbid obesity are predictors of increased mortality after heart transplantation

BACKGROUND

Extremes in body weight are a relative contraindication to cardiac transplantation.

METHODS

We retrospectively reviewed 474 consecutive adult patients (377 male, 97 female, mean age 50.3+/-12.2 years), who received 444 primary and 30 heart retransplants between January of 1992 and January of 1999. Of these, 68 cachectic (body mass index [BMI]<20 kg/m2), 113 overweight (BMI=>27-30 kg/m2), and 55 morbidly obese (BMI>30 kg/m2) patients were compared with 238 normal-weight recipients (BMI=20-27 kg/m2). We evaluated the influence of pretransplant BMI on morbidity and mortality after cardiac transplantation. Kaplan-Meier survival distribution and Cox proportional hazards model were used for statistical analyses.

RESULTS

Morbidly obese as well as cachectic recipients demonstrated nearly twice the 5-year mortality of normal-weight or overweight recipients (53% vs. 27%, respectively, P=0.001). An increase in mortality was seen at 30 days for morbidly obese and cachectic recipients (12.7% and 17.7%, respectively) versus a 30-day mortality rate of 7.6% in normal-weight recipients. Morbidly obese recipients experienced a shorter time to high-grade acute rejection (P=0.004) as well as an increased annual high-grade rejection frequency when compared with normal-weight recipients (P=0.001). By multivariable analysis, the incidence of transplant-related coronary artery disease (TCAD) was not increased in morbidly obese patients but cachectic patients had a significantly lower incidence of TCAD (P=0.05). Cachectic patients receiving oversized donor hearts had a significantly higher postoperative mortality (P=0.02).

CONCLUSIONS

The risks of cardiac transplantation are increased in both morbidly obese and cachectic patients compared with normal-weight recipients. However, the results of cardiac transplantation in overweight patients is comparable to that in normal-weight patients. Recipient size should be kept in mind while selecting patients and the use of oversized donors in cachectic recipients should be avoided.

Weight gain and cardiovascular risk after organ transplantation

Organ transplantation has become a common and effective approach to the management of patients with organ failure. The improvement in long-term survival has resulted in the emergence of cardiovascular disease as the primary cause of death in renal transplant patients and a significant complication in other organ recipients. A number of factors explain this trend, including a high incidence of hypertension, posttransplant diabetes, hyperlipidemia, and obesity-risk factors that are mediated by direct effects of immunosuppressive medications. Weight gain posttransplant affects approximately 50% of patients and represents a significant problem because of the potential synergism between obesity and immunosuppressive medication-induced effects on cardiovascular disease risk factor development. This review discusses the incidence and implications of cardiovascular disease risk factors in organ transplant recipients, strategies for clinical management, and future research directions.

Lessons learned from more than 1,000 pancreas transplants at a single institution

OBJECTIVE

To determine outcome in diabetic pancreas transplant recipients according to risk factors and the surgical techniques and immunosuppressive protocols that evolved during a 33-year period at a single institution.

SUMMARY BACKGROUND DATA

Insulin-dependent diabetes mellitus is associated with a high incidence of management problems and secondary complications. Clinical pancreas transplantation began at the University of Minnesota in 1966, initially with a high failure rate, but outcome improved in parallel with other organ transplants. The authors retrospectively analyzed the factors associated with the increased success rate of pancreas transplants.

METHODS

From December 16, 1966, to March 31, 2000, the authors performed 1,194 pancreas transplants (111 from living donors; 191 retransplants): 498 simultaneous pancreas-kidney (SPK) and 1 simultaneous pancreas-liver transplant; 404 pancreas after kidney (PAK) transplants; and 291 pancreas transplants alone (PTA). The analyses were divided into five eras: era 0, 1966 to 1973 (n = 14), historical; era 1, 1978 to 1986 (n = 148), transition to cyclosporine for immunosuppression, multiple duct management techniques, and only solitary (PAK and PTA) transplants; era 2, 1986 to 1994 (n = 461), all categories (SPK, PAK, and PTA), predominantly bladder drainage for graft duct management, and primarily triple therapy (cyclosporine, azathioprine, and prednisone) for maintenance immunosuppression; era 3, 1994 to 1998 (n = 286), tacrolimus and mycophenolate mofetil used; and era 4, 1998 to 2000 (n = 275), use of daclizumab for induction immunosuppression, primarily enteric drainage for SPK transplants, pretransplant immunosuppression in candidates awaiting PTA.

RESULTS

Patient and primary cadaver pancreas graft functional (insulin-independence) survival rates at 1 year by category and era were as follows: SPK, era 2 (n = 214) versus eras 3 and 4 combined (n = 212), 85% and 64% versus 92% and 79%, respectively; PAK, era 1 (n = 36) versus 2 (n = 61) versus 3 (n = 84) versus 4 (n = 92), 86% and 17%, 98% and 59%, 98% and 76%, and 98% and 81%, respectively; in PTA, era 1 (n = 36) versus 2 (n = 72) versus 3 (n = 30) versus 4 (n = 40), 77% and 31%, 99% and 50%, 90% and 67%, and 100% and 88%, respectively. In eras 3 and 4 combined for primary cadaver SPK transplants, pancreas graft survival rates were significantly higher with bladder drainage (n = 136) than enteric drainage (n = 70), 82% versus 74% at 1 year (P =.03). Increasing recipient age had an adverse effect on outcome only in SPK recipients. Vascular disease was common (in eras 3 and 4, 27% of SPK recipients had a pretransplant myocardial infarction and 40% had a coronary artery bypass); those with no vascular disease had significantly higher patient and graft survival rates in the SPK and PAK categories. Living donor segmental pancreas transplants were associated with higher technically successful graft survival rates in each era, predominately solitary (PAK and PTA) in eras 1 and 2 and SPK in eras 3 and 4. Diabetic secondary complications were ameliorated in some recipients, and quality of life studies showed significant gains after the transplant in all recipient categories.

CONCLUSIONS

Patient and graft survival rates have significantly improved over time as surgical techniques and immunosuppressive protocols have evolved. Eventually, islet transplants will replace pancreas transplants for suitable candidates, but currently pancreas transplants can be applied and should be an option at all stages of diabetes. Early transplants are preferable for labile diabetes, but even patients with advanced complications can benefit.

Nutritional assessment of the lung transplant patient: body mass index as a predictor of 90-day mortality following transplantation

BACKGROUND

It is well documented that malnourished and/or obese surgical patients have increased morbidity and mortality post-operatively. Only a few studies investigating the effect of nutritional status on mortality are available pertaining to the transplant population. Since limited data are available on the nutritional status and its effects on mortality in the lung transplant population, we sought to ascertain whether there is an association between mortality and preoperative nutritional status.

METHODS

We examined mortality during the first 3 months after transplantation. Patients were grouped by body mass index (BMI) categories as < 17 kg/m(2), 17 to < 20 kg/m(2), 20 to 25 kg/m(2) (reference group), > 25 to 27 kg/m(2), and > 27 kg/m(2). Additional risk factors retrieved from the pre-transplant records included age, gender, diagnosis, energy requirements, protein requirements, protein and caloric intake, and weight history. Logistic regression for univariate and multivariate analysis for mortality used recipient age, gender, disease category, pre-transplant cytomegalovirus (CMV) serology, transplant type (single or bilateral), and donor age, gender, and CMV serology.

RESULTS

The likelihood estimates or odds ratios (ORs) of the risk of death within 90 days of lung transplantation for the BMI categories compared to the reference group were 3.7 for BMI < 17 kg/m(2) (p = 0.085), 1.6 for BMI < 17 to 20 kg/m(2) (p = 0.455), 3.5 for BMI > 25 to 27 kg/m(2) (p = 0.069), and 5.0 for BMI > 27 kg/m(2) (p = 0.003).

CONCLUSIONS

In patients with a pre-transplant BMI < 17 kg/m(2) or > 25 kg/m(2) the risk of dying within 90 days post-transplant was increased. In patients with a pre-transplant BMI of > 27 kg/m(2) the risk was significantly higher in than the reference group.

Anthropometric measures and risk of death in children with end-stage renal disease

We evaluated the association between anthropometric measurements and death among pediatric patients with end-stage renal disease (ESRD) using data from the Pediatric Growth and Development Special Study (PGDSS) from the US Renal Data System. Height, growth velocity, and body mass index (BMI) were used for the analysis of 1,949 patients in the PGDSS. To standardize these measurements, SD scores (SDSs) were calculated using population data from the Third National Health and Nutrition Examination Survey. Using Cox proportional hazards models, we assessed the association between anthropometric measures and death, controlling for demographic factors and stratifying by age. Multivariate analysis showed that each decrease by 1 SDS in height was associated with a 14% increase in risk for death (adjusted relative risk [aRR], 1.14; 95% confidence interval [CI], 1.02 to 1.27; P = 0.017). For each 1 SDS decrease in growth velocity among patients in our sample, the risk for death increased by 12% (aRR, 1.12; 95% CI, 1.00 to 1.25; P = 0.043). There was a statistically significant U-shaped association between BMI and death (P = 0.001), with relatively low and high BMIs associated with an increased risk for death. In children with ESRD, growth delay and extremes in BMI are associated with an increased risk for mortality.

The effect of body mass index on long-term renal allograft survival

BACKGROUND

A number of factors have been implicated in decreasing long-term renal graft survival. Factors such as living versus cadaveric donor status, acute rejection, and HLA matching have been studied in detail. Mild obesity defined as a body mass index (BMI) of >25 has been found to have a deleterious effect on a number of physiologic processes. We studied the effect of a BMI >25 on long-term renal transplantation outcome.

METHODS

A total of 405 patients who underwent transplantation at Saint Barnabas Medical Center from 1990 to 1997 were evaluated. All known variables impacting on long-term graft function were collected. Multivariate analysis utilizing the Cox-proportional hazard model and Kaplan-Meier actuarial survival were applied to these risk factors.

RESULTS

BMI >25 was isolated as an independent risk factor for both decreased graft survival and patient survival (relative risk 2.0 for each). Cadaveric donor status, acute rejection, and use of azathioprine versus mycophenolate mofetil were the only other significant risk factors.

CONCLUSIONS

Mild obesity before transplantation has a negative impact on long-term renal graft and patient survival.

Are preoperative obesity and cachexia risk factors for post heart transplant morbidity and mortality: a multi-institutional study of preoperative weight-height indices. Cardiac Transplant Research Database (CTRD) Group

BACKGROUND

The relationship between pre-transplant body weight and post-transplant outcome has only recently been identified using a single, indirect measure of weight (percent ideal body weight [PIBW]). The literature is equivocal regarding which index is the better indicator of body weight. The purpose of this study was to determine (1) if pre-heart transplant body weight, measured by body mass index (BMI) and PIBW, is associated with post-heart transplant morbidity and mortality and (2) if patient gender, age, and etiology of heart disease affect this association.

METHODS

The sample included 4,515 patients who received a heart transplant from January 1, 1990-December 31, 1995 at 38 institutions participating in the Cardiac Transplant Research Database (CTRD). Patients were divided into groups according to their BMI and PIBW. Data were described using frequencies, measures of central tendency, Pearson correlation coefficients, stratified actuarial analyses and log rank tests for comparisons, and a multivariable risk factor analysis in the hazard domain.

RESULTS

For all patients (n = 4,515), being <80% or >140% of IBW before heart transplant was a risk factor for increased mortality after heart transplant. The association between pre-heart transplant PIBW and post-heart transplant survival was affected by gender, age, and etiology of heart disease. In males, a higher PIBW was a significant risk factor for death early after transplant (p = .0003). Although not significant, there was a trend for a higher PIBW being a risk factor for death in females throughout the post transplant period (p = .07). No differences in cause of death were found for PIBW and BMI. In male and female recipients <55 years, being overweight pre-heart transplant was a risk factor for infection. In patients with pre-transplant ischemic heart disease, the greatest risk for infection was found in patients who were >140% of IBW. Pre-heart transplant BMI and PIBW were not associated with acute rejection or cardiac allograft arteriopathy after transplant.

CONCLUSIONS

In conclusion, being cachectic or obese preoperatively is associated with decreased survival in all patients after heart transplantation. Being obese preoperatively is associated with increased infection after heart transplant in males and females <55 years and in patients with ischemic heart disease. Of the 2 indices of body weight used in this study, percent ideal body weight appears to be the better predictor of future morbidity and mortality following heart transplantation.

The importance of obesity and hyperlipidaemia in patients with renal transplants

The authors studied dyslipidaemia and "obesity" in 137 patients (87 males and 50 females) following cadaver renal transplantation with regard to the applied immunosuppressive treatment and the patients' hypertension. The most extreme dyslipidaemic values, the highest levels of total cholesterol, LDL and Apo were found 6 to 18 months after successful transplantation; these values were significantly higher in women than in men. While in the dialysis programme only 21.89% of the patients had BMI values higher than 25.1 kg/m2, after transplantation their proportion was 36.49%. In addition to hyperlipidaemia, hyperuricaemia was encountered in 39.42%, erythrocytosis in 8.76% and diabetes mellitus in 9.48%, respectively. In the group of patients treated only with Cyclosporine-A the incidence of hyperlipidaemia and hypertension was significantly lower than in those receiving a combination of either corticosteroids and Cyclosporine-A or corticosteroids, Cyclosporine-A and azathioprine. There was a close relationship between the unfavourable tendency of obesity and the measured hyperlipidaemia. On the other hand, the extent of proteinuria did not always have a positive correlation with the increase of BMI and body weight, the severity of hypertension and hyperlipidaemia. The authors emphasize the importance of a systematic control of the lipid levels, the significance of a diet with an adequate carbohydrate and lipid content, and the necessity of avoiding obesity by selecting the optimal immunosuppressive treatment.