Pre- and post-transplant factors associated with body weight parameters after liver transplantation – A systematic review and meta-analysis

First Testing of Literature-Based Models for Predicting Increase in Body Weight and Adipose Tissue Mass After Kidney Transplantation

Introduction: Weight gain is a risk factor for poor clinical outcomes following kidney transplantation. Research Question: This study's aim was a first testing of 2 models to identify patients early after kidney transplantation who are at risk for weight gain and increase in adipose tissue mass in the first year after kidney transplantation. Design: The literature-based models were evaluated on longitudinal data of 88, respectively 79 kidney transplant recipients via ordinary and Firth regression, using gains ≥ 5% in weight and adipose tissue mass respectively as primary and secondary endpoints. Results: The models included physical activity, smoking cessation at time of kidney transplantation, self-reported health status, depressive symptomatology, gender, age, education, baseline body mass index and baseline trunk fat as predictors. Area under the curve was 0.797 (95%-CI 0.702 to 0.893) for the weight model and 0.767 (95%-CI 0.656 to 0.878) for the adipose tissue mass model-showing good, respectively fair discriminative ability. For weight gain ≥ 5%, main risk factors were smoking cessation at time of transplantation (OR 16.425, 95%-CI 1.737-155.288) and better self-reported baseline health state (OR 1.068 for each 1-unit increase, 95%-CI 1.012-1.128). For the adipose tissue mass gain ≥ 5%, main risk factor was overweight/obesity (BMI ≥ 25) at baseline (odds ratio 7.659, 95%-CI 1.789-32.789). Conclusions: The models have potential to assess patients' risk for weight or adipose tissue mass gain during the year after transplantation, but further testing is needed before implementation in clinical practice.

Bariatric surgery outcomes following organ transplantation: A review study

Weight gain is a frequent postoperative complication following a solid organ transplant which can be solved by bariatric surgery. The outcomes of bariatric surgery among patients with an organ transplant history are always a challengeable subject for surgeons and surgery candidates. In this review article, we aim to investigate the existence literature about the rates of morbidity and mortality, frequent complications in terms of graft function, remission in diabetes, hypertension, pulmonary and cardiovascular disorders, hepatic and renal functions, and immunosuppressive stability, as well as the safety of bariatric surgery among patients.

Designing and Psychometric Properties of Appraisal Adherence to Care and Treatment Scale in Liver Transplantation Recipients

Background: Care and treatment adherence are important factors for given good liver transplantation outcomes. Objectives: Design and validate an instrument to appraise adherence to care and treatment in liver transplantation recipients. Methods: A mixed-methods sequential exploratory study was conducted in two phases from 2017 to 2019, in the Liver Transplantation Clinic Tehran, Iran. In the qualitative phase, the concept of care and treatment adherence in liver transplantation recipients extracted by a conventional content analysis was performed on semi-structural interviews that were conducted on 18 liver transplantation recipients that were recruited through purposive sampling technique. Also, two physicians, one nurse coordinator of the liver transplantation team, and two family members were interviewed. The scale was developed based on operational definitions extracted from the qualitative phase. The validity was assessed by face, content, construct validity, and confirmatory factor analysis. The reliability was also evaluated by calculating test-retest intraclass correlation coefficient and Cronbach's alpha. The exploratory factor analysis was carried out with 286 filled the questionnaire. Results: Four factors were extracted in factor analysis. These factors explained 45.622% of the variance. The final version of the scale consisted of 20 items. The Cronbach's alpha coefficient reported as 0.889 for the total scale and the intraclass correlation coefficient was reported as 0.912. The confirmatory factor analysis led to a fitting model. Chi-square indices were reported as CMIN/DF = 2.34, NFI = 0.94, CFI = 0.96, and RAMSEA = 0.067. Conclusions: With a four factors structure, validity and reliability of adherence to care and treatment scale are acceptable; therefore, it can be used for appraisal care and treatment adherence in liver transplant recipients.

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Body Weight Parameters are Related to Morbidity and Mortality After Liver Transplantation: A Systematic Review and Meta-analysis

BACKGROUND

Weight gain and obesity are well-known clinical issues in liver transplantation (LTx). However, their impacts on patient outcomes remain unclear, as only the impact of pre-LTx body mass index (BMI) on survival has been meta-analyzed. We summarized and synthesized the evidence on pre- and post-LTx body weight parameters' relations with post-LTx outcomes such as survival, metabolic and cardiovascular comorbidities, and healthcare utilization.

METHODS

We followed the Cochrane Handbook for Systematic Reviews of Interventions' recommendations. Quality was assessed via a 19-item instrument. Odds ratios and 95% confidence intervals were calculated for outcomes investigated in ≥5 studies.

RESULTS

Our meta-analysis included 37 studies. Patients with pre-LTx BMI ≥ 30 kg/m and BMI ≥ 35 kg/m had lower overall survival rates than those with pre-LTx normal weight (72.6% and 69.8% versus 84.2%; P = 0.02 and P = 0.03, respectively). Those with pre-LTx BMI ≥ 30 kg/m had worse overall graft survival than normal weight patients (75.8% and 85.4%; P = 0.003). Pre-LTx BMI and pre-LTx overweight were associated with new-onset diabetes (P < 0.001 and P = 0.015, respectively), but post-LTx BMI showed no relationship. No associations were evident with healthcare utilization.

CONCLUSIONS

Patients with BMI values ≥30 kg/m had worse patient and graft survival than those with normal weight. Few of the reviewed studies examined post-LTx body weight parameters or other relevant outcomes such as cardiovascular comorbidities. High heterogeneity as well as diverse definitions and operationalizations of measurement and outcomes severely impeded comparability.

Post-transplant obesity impacts long-term survival after liver transplantation

BACKGROUND

Short-term survival after orthotopic liver transplantation (OLT) has improved over the past decades, but long-term survival remains impaired. The effects of obesity on long-term survival after OLT are controversial. Because pre-transplant body mass index (BMI) can be confounded by ascites, we hypothesized that post-transplant BMI at 1 year could predict long-term survival.

METHODS

A post-hoc analysis was performed of an observational cohort study consisting of adult recipients of a first OLT between 1993 and 2010. Baseline BMI was measured at 1-year post-transplantation to represent a stable condition. Recipients were stratified into normal weight (BMI < 25 kg/m²), overweight (25 ≤ BMI ≤ 30 kg/m²), and obese (BMI > 30 kg/m²). Kaplan-Meier survival analyses were performed with log-rank testing, followed by multivariable Cox proportional hazards regression analysis.

RESULTS

Out of 370 included recipients, 184 had normal weight, 136 were overweight, and 50 were obese at 1-year post-transplantation. After median follow-up for 12.3 years, 107 recipients had died, of whom 46 (25%) had normal weight, 39 (29%) were overweight, and 22 (44%) were obese (log-rank P = 0.020). Obese recipients had a significantly increased mortality risk compared to normal weight recipients (HR 2.00, 95% CI 1.08-3.68, P = 0.027). BMI was inversely associated with 15 years patient survival (HR 1.08, 95% CI 1.03-1.14, P = 0.001 per kg/m²), independent of age, gender, muscle mass, transplant characteristics, cardiovascular risk factors, kidney- and liver function.

CONCLUSION

Obesity at 1-year post-transplantation conveys a 2-fold increased mortality risk, which may offer potential for interventional strategies (i.e. dietary advice, lifestyle modification, or bariatric surgery) to improve long-term survival after OLT.

Non-alcoholic fatty liver disease after liver transplantation in patients with non-alcoholic steatohepatitis and cryptogenic cirrhosis: the impact of pre-transplant graft steatosis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) may occur in liver transplant recipients. This study aimed to investigate the prevalence and risk factors of NAFLD after liver transplantation in patients with NASH and cryptogenic cirrhosis, focusing on the impact of graft steatosis.

METHODS

Patients with NASH and cryptogenic cirrhosis who had undergone liver transplantation in Shiraz transplant center between March 2010 and March 2017 were included. NAFLD was diagnosed after liver transplantation using ultrasonography and transient elastography.

RESULTS

73 patients with NASH and 389 with cryptogenic cirrhosis were included. NAFLD was diagnosed in 33 patients (56.9%) in NASH group and 96 patients (26.7%) in cryptogenic group (OR: 3.61; CI: 2.04-6.39; P-Value < 0.001), using ultrasound. Obesity and post-transplant hyperlipidemia were independent predictors of NAFLD after liver transplantation (P < 0.05). NAFLD was diagnosed in 32.9% of patients with graft macrosteatosis compared to 29.9% in patients without graft macrosteatosis (OR: 1.51; 95%CI: 0.755-1.753). 28% of the patients with macrosteatosis ≥30% had NAFLD after liver transplantation compared to 31.4% with macrosteatosis <30% (OR: 1.175; 95% CI: 0.346-2.091).

CONCLUSION

Liver graft steatosis before transplantation was not associated with the occurrence of NAFLD after liver transplantation.