The impact of obesity is becoming increasingly important in kidney transplantation

- Research

A study by the Nephrology Department of the Bellvitge University Hospital (HUB) highlights the need to raise awareness among both transplant candidates and potential donors

In the last half century, obesity has increased by 5-10% in the male population and by 8-14% in the female population. According to different estimates, more than 650 million people have obesity issues. This increase in the prevalence of obesity has also been reflected in kidney transplant donors and recipients. The Nephrology Service of the Bellvitge University Hospital has published a study in the journal Nephron that reviews the latest published works on the increasing impact of obesity on the different stages and actors involved in kidney transplantation.

One of the main conclusions of the review carried out by the nephrologists of the Bellvitge University Hospital is that weight loss is a requirement that should become much more relevant as a step prior to transplantation. In this sense, they stress the need to include more explicitly in transplant clinical guidelines, and as a campaign to raise awareness among candidates, the importance of prior weight loss, along with physical exercise and a healthy diet. "Transplantation is the treatment that provides the best quality of life for people with severe chronic kidney disease. Recent studies show that losing weight once the kidney has been received does not lead to significant improvements in graft survival," explains Dr. María Quero, from the Nephrology Department at the HUB.

Haemodialysis patients encounter a phenomenon of reverse epidemiology: obesity and other cardiovascular risk factors play a certain protective role against their kidney disease. However, renal transplantation is the best possible long-term treatment, as evidenced by previous work reviewed for the study.


Obesity appears as one of the assessment criteria for patients who are candidates for kidney transplantation. It is a major risk factor for cardiovascular and other metabolic disorders. Renal transplantation increases the survival of patients with chronic kidney disease, but still 17% of deaths in kidney transplant recipients are due to a cardiovascular disease.

A body mass index (BMI) of 30-35 or higher may result in a person with chronic kidney disease being on the waiting list for longer or, in case of morbid obesity levels, being unsuitable to be added to the very list. Although obesity is related to complications in renal transplantation, different studies analysed in this work lead to the conclusion that transplantation also improves the survival of obese patients with chronic kidney disease. In this sense, the Bellvitge University Hospital's study stresses the convenience of not using BMI as the sole criterion for classifying patients on waiting lists. Instead, it suggests analysing each case individually and taking into account other factors that may explain weight gain, such as fluid accumulation or muscle mass distribution.