Increasing evidence that the survival rates of most obese people who receive kidney transplants are similar to those of other patients raises questions about the common practice of denying surgery until after they lose weight.
A new study in the American Journal of Transplantation shows that patients with kidney failure and a body mass index (BMI) of 30–39 experience a similar survival advantage from transplantation as nonobese patients: a more than 66% reduced risk of dying within a year (http://doi.wiley.com/10.1111/ajt.12331). The study of 208 498 American patients also reveals that those with BMIs over 40 had a 48% reduced risk of dying, although this difference in benefit was less profound when patients received kidneys from live donors.
“There is a difference in how we evaluate and refer patients who are obese, and I think there’s potential bias there, but it’s not been examined in the Canadian context,” says nephrologist Dr. John Gill, a coauthor of the study and president of the Canadian Organ Replacement Registry. “Hopefully this study will reinforce that these patients do derive an equivalent survival benefit from being transplanted ... and make us think twice about just turfing them.”
Most Canadian transplant centres will not consider obese patients for kidney transplant unless those patients first lose weight, citing the increased difficulty of the procedure and risk of complications (www.cmaj.ca/lookup/doi/10.1503/cmaj.109-3957).
“It’s not discrimination against obesity; it’s discrimination because it’s a higher-risk procedure, just like operating on someone with a lot of medical problems is a higher-risk procedure,” explains Dr. Jeffrey Zaltzman, director of renal transplants at St. Michael’s Hospital in Toronto, Ontario, and chief medical officer for Trillium Gift of Life Network, Ontario’s organ and tissue donation agency. “You’re not saying, ‘No.’ You’re just saying, ‘No for now.’”
The nature of providing donor transplantations in a team environment also requires setting standards that everyone can agree to, Zaltzman adds. “If one surgeon signs off on a patient, but he’s not the one doing the operation because … he’s not there [when the kidney becomes available], his colleague has to be comfortable with the same decision.”
Others argue it’s time for a national reassessment of the reluctance to provide transplants for obese patients, particularly as obesity is increasing in people with kidney failure.
“We’ve known for many years now that transplantation offers a benefit for most patients, including obese patients, and obesity is an issue that’s going to grow,” says Dr. Jean Tchervenkov, a transplant surgeon at the McGill University Health Centre in Montréal, Quebec. “I think we can all agree that transplants will help and if a patient remains on dialysis for a long time that’s not good either.”
Gill argues it is “hollow” to tell patients to lose weight when the very nature of their conditions makes it difficult, if not impossible.
“Being on dialysis, these patients are not going to do a lot of physical activity, and they may have diabetes or other conditions that limit their ability to lose weight successfully,” he explains. “Transplant programs are really not equipped to help people ... implement lifestyle changes.”
Bariatric surgery and better post-transplant care — including reducing exposure to steroids and other drugs that impair wound healing, and providing aggressive physiotherapy to mobilize patients as quickly as possible — could reduce risks for obese patients.
Increased access to live donor transplants could also improve outcomes, as many obese patients are passed over for this safer type of transplant, says Gill. “We don’t know if it’s because their doctors are not pushing for it as aggressively as they might for a leaner patient, or if donors have concerns about donating to someone who is obese, or if obesity runs in families, so a patient may have fewer living donors available to them from a genetic perspective. There’s a whole set of questions that needs further research.”