Body mass index and outcome in renal transplant recipients: a systematic review and meta-analysis

Abstract

BackgroundWhether overweight or obese end stage renal disease (ESRD) patients are suitable for renal transplantation (RT) is often debated. The objective of this review and meta-analysis was to systematically investigate the outcome of low versus high BMI recipients after RT.MethodsComprehensive searches were conducted in MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and CENTRAL (the Cochrane Library 2014, issue 8). We reviewed four major guidelines that are available regarding (potential) RT recipients. The methodology was in accordance with the Cochrane Handbook for Systematic Reviews of Interventions and written based on the PRISMA statement. The quality assessment of studies was performed by using the GRADE tool. A meta-analysis was performed using Review Manager 5.3. Random-effects models were used.ResultsAfter identifying 5,526 studies addressing this topic, 56 studies were included. We extracted data for 37 outcome measures (including data of more than 209,000 RT recipients), of which 26 could be meta-analysed. The following outcome measures demonstrated significant differences in favour of low BMI (<30) recipients: mortality (RR = 1.52), delayed graft function (RR = 1.52), acute rejection (RR = 1.17), 1-, 2-, and 3-year graft survival (RR = 0.97, 0.95, and 0.97), 1-, 2-, and 3-year patient survival (RR = 0.99, 0.99, and 0.99), wound infection and dehiscence (RR = 3.13 and 4.85), NODAT (RR = 2.24), length of hospital stay (2.31 days), operation duration (0.77 hours), hypertension (RR = 1.35), and incisional hernia (RR = 2.72). However, patient survival expressed in hazard ratios was in significant favour of high BMI recipients. Differences in other outcome parameters were not significant.ConclusionsSeveral of the pooled outcome measurements show significant benefits for ‘low’ BMI (<30) recipients. Therefore, we postulate that ESRD patients with a BMI >30 preferably should lose weight prior to RT. If this cannot be achieved with common measures, in morbidly obese RT candidates, bariatric surgery could be considered.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-015-0340-5) contains supplementary material, which is available to authorized users.

Obesity-Associated Adipose Tissue Inflammation and Transplantation

“…In terms of survival, obese patients tend to have no decrease in short-term survival but may have attenuated overall survival; however, whether this is related to a decrease in graft function or other obesity-related effects is undetermined (27,33). In terms of graft survival, acute rejection tends to be increased in obese patients (27,34,37), and obesity is associated with delayed graft function in kidney transplantation (29)(30)(31)(32), hepatocellular carcinoma in liver transplants (27,33), and grade III primary graft dysfunction in lung transplants (27).…”

Overweight Kidney Transplant Recipients Are at Risk of Being Overdosed Following Standard Bodyweight-Based Tacrolimus Starting Dose

“…11 Overweight kidney transplant recipients have an increased mortality, more delayed graft functions, more acute rejection episodes, more wound infections, and a longer hospital stay compared with patients with a body mass index (BMI) of less than 30. 12 The kidney disease improving global outcomes Transplant Workgroup states that dosing of Tac is important and that it is relatively underinvestigated. 1 Although the Tac starting dose is based on bodyweight in many centers, dosing algorithms have demonstrated that bodyweight does not have a statistically significant influence on Tac clearance.…”

Challenges Associated with Managing End-Stage Renal Disease in Extremely Morbid Obese Patients: Case Series and Literature Review

“…Currently, many transplant centers use BMI as a selection criterion with a range of 35-45 kg/m 2 as the upper limit to initiate evaluation for renal transplantation [34] . A recent meta- analysis showed that graft and patient survival are worse in renal transplant recipients with a higher BMI [35] . Losing weight prior to renal transplantation has great importance and intentional weight loss can be recommended.…”