Pretransplant Obesity: A Weighty Issue Affecting Transplant Candidacy and Outcomes

Abstract

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.

Can New-Onset Diabetes After Kidney Transplant Be Prevented?

“…The national secular trend toward overweight and obesity extends to patients with ESRD who are seeking kidney transplantation, resulting in higher body weight before transplant and thereby increasing the risk of NODAT(12). In fact, in the U.S., the prevalence of obesity (BMI ≥30 kg/m 2 ) among transplant recipients at the time of kidney transplantation doubled between 1987 and 2001 (13). Thus, a higher number of obese patients receiving transplants, now and in the future, may contribute to growth in the incidence rate of NODAT.…”

“…Type 2 diabetes mellitus and NODAT share similar risk factors, especially obesity. The prevalence of obesity (BMI ≥30 kg/m 2 ) at the time of transplantation among transplant recipients in the U.S. has doubled between 1987 and 2001 (13). Because higher BMI before transplant correlates with insulin resistance after transplantation, obesity treatment seems to be reasonable target for intervention.…”

Allogeneic transplant outcomes are not affected by body mass index (BMI) in patients with haematological malignancies

“…Obese individuals have larger absolute lean body and fat masses than non-obese individuals of the same age, gender and height, which might lead to altered pharmacokinetics of chemotherapeutic agents [1]. Although obesity seems to provide a survival benefit in dialysis patients, obesity has traditionally been considered a contraindication for transplantation of both bone marrow transplant recipients as well as solid organ transplants [2]. It was widely adopted that obesity will contribute to worse transplant outcomes, including lower rates of engraftment and patient survival and higher rates of delayed graft function and infection [3].…”

Malnutrition and Sarcopenia in Advanced Liver Disease

“…This seemingly paradoxical finding may be because their body fat was retained while muscle atrophy was occurring. Many transplant centers defer patients from transplant listing until BMI is less than 35 because of comorbidities associated as diabetes [24]. The United Network for Organ Sharing provided data has shown that, in the past decade, the obesity-associated liver disease has become an increasing indication for transplantation.…”