Impact of obesity on renal transplant outcomes

Obesity is a frequent and important consideration to be taken into account when assessing patient suitability for renal transplantation. In addition, posttransplant obesity continues to represent a significant challenge to health care professionals caring for renal transplant recipients. Despite the vast amount of evidence that exists on the effect of pretransplant obesity on renal transplant outcomes, there are still conflicting views regarding whether obese renal transplant recipients have a worse outcome, in terms of short- and long-term graft survival and patient survival, compared with their non-obese counterparts. It is well established that any association of obesity with reduced patient survival in renal transplant recipients is mediated in part by its clustering with traditional cardiovascular risk factors such as hypertension, dyslipidaemia, insulin resistance and posttransplant diabetes mellitus, but what is not understood is what mediates the association of obesity with graft failure. Whether it is the higher incidence of cardiovascular comorbidities jeopardising the graft or factors specific to obesity, such as hyperfiltration and glomerulopathy, that might be implicated, currently remains unknown. It can be concluded, however, that pre- and posttransplant obesity should be targeted as aggressively as the more well-established cardiovascular risk factors in order to optimize long-term renal transplant outcomes.