Obese Patients Wait Longer for Kidney Transplants, Research Suggests

New research from Johns Hopkins specialists suggests that obese kidney disease patients face not only the usual long odds of a tissue match and organ rejection, but also are significantly less likely than normal-weight people to receive a kidney transplant at all.

The Johns Hopkins study results, to be published online this Wednesday in the Journal of the American Society of Nephrology, reveal that morbidly obese patients (those who on average weigh 100 pounds more than their ideal weight) are on the transplant waiting list for a median of five years - two years more than the median wait time for a patient of normal weight.

Because patients tend to get sicker the longer they wait on dialysis, obese patients are 44 percent less likely than normal-weight patients to ever receive a kidney transplant, the researchers report. Each year, 8 percent of the patients on the list die waiting for a kidney.

Johns Hopkins transplant surgeon Dorry Segev, M.D., who led the study, suggests that obese patients might be turned down, sometimes multiple times, because of the added cost and poorer outcome associated with transplants in overweight patients.

“Being overweight should not be a disqualifying and discriminating factor against these patients,” Segev says.

He adds that at Johns Hopkins, the rate at which overweight, severely obese, and morbidly obese patients are listed and receive transplants is much higher than the national average. As a result, the waiting times for obese patients are not significantly different.

“Patients understandably believe that being placed on the transplant waiting list is an implicit promise of fair, unbiased treatment under a transparent allocation scheme,” Segev says. “Unfortunately, the system that has been established nationally may not be living up to that promise.”

The study’s findings may be explained, he says, by economic pressures as well as medical ones. He notes that Medicare - the principal insurer for kidney transplants - pays a set amount for the operation regardless of a patient’s overall health, difficulty of the operation, length of stay, postoperative care and complications, all of which may increase substantially with obese patients. Transplant centers, therefore, may be under pressure to avoid operating on these individuals.

In addition, Segev says, centers with lower surgical survival rates overall risk losing Medicare funding.

The researchers analyzed data from 132,353 men and women with kidney disease who were on the United Network for Organ Sharing (UNOS) deceased donor kidney transplantation list from 1995 to 2006 in the United States.

Patients’ weight was rated using the body mass index (BMI) scale - weight in kilograms divided by height in meters squared. A normal BMI is 18.5. Overweight is 25 (25 to 30), obese is 30 to 35 severely obese is 35 to 40 and morbidly obese is 40 to 60.