Reduced Calorie Diet Intervention in Kidney Transplant Recipients

Kidney transplantation is the preferred renal replacement therapy for end stage renal disease (ESRD) because it affords survival and quality of life advantages over maintenance dialysis.1 The number of transplants performed increases each year, with currently over 150,000 individuals living in the United States with a kidney transplant. This is in the setting of 68,000 patients on the wait list with a median wait time of 4 years for an available organ.2 Despite the survival benefit over dialysis, transplanted patients still have a greatly increased risk of cardiovascular disease (CVD) over the general population, and CVD is the leading cause of death among recipients with a functioning graft.3 Given the long wait times for kidneys due to organ shortage, extensive resources used, and support needed for each transplant procedure, it is imperative that we improve long term patient and graft survival. Accordingly, modification of CVD risk profile is of paramount importance in kidney transplant patients.

The etiology of increased risk of CVD in kidney transplant patients is multi-factorial and includes the high burden of CVD and its risk factors present prior to transplant, as well as increasing prevalence of these risk factors in the post transplant period due to transplant associated weight gain, immunosuppression side effects, metabolic consequences of a functioning kidney, and allograft dysfunction. Efforts to reduce CVD risk factors have yet to be adequately implemented and rigorously studied in the kidney transplant population.

Obesity at the time of transplant is common and associated with several CVD risk factors post transplant, including hypertension, hyperlipidemia, diabetes mellitus, metabolic syndrome, and inflammation. Obesity is also associated with potentially poorer graft outcomes, including death censored graft loss and chronic allograft failure.4 In addition, the majority of patients gain weight post transplantation, primarily in the form of fat mass. Post transplant weight gain is also associated with increased prevalence of known CVD risk factors, CVD death, and graft loss.5 The increased burden of CVD in kidney transplant patients makes obesity prevention and treatment strategies appealing interventions to improve long-term outcomes, both in terms of graft and overall survival. In this study we will measure the effect of a low calorie diet intervention in new kidney transplant recipients on the outcomes weight gain, oxidative stress, and insulin resistance.