Reduction in energy expenditure after liver transplantation

From Listing to Recovery: A Review of Nutritional Status Assessment and Management in Liver Transplant Patients

Liver transplantation (LT) is a complex surgical procedure requiring thorough pre- and post-operative planning and care. The nutritional status of the patient before, during, and after LT is crucial to surgical success and long-term prognosis. This review aims to assess nutritional status assessment and management before, during, and after LT, with a focus on patients who have undergone bariatric surgery. We performed a comprehensive topic search on MEDLINE, Ovid, In-Process, Cochrane Library, EMBASE, and PubMed up to March 2023. It identifies key factors influencing the nutritional status of liver transplant patients, such as pre-existing malnutrition, the type and severity of liver disease, comorbidities, and immunosuppressive medications. The review highlights the importance of pre-operative nutritional assessment and intervention, close nutritional status monitoring, individualised nutrition care plans, and ongoing nutritional support and monitoring after LT. The review concludes by examining the effect of bariatric surgery on the nutritional status of liver transplant recipients. The review offers valuable insights into the challenges and opportunities for optimising nutritional status before, during, and after LT.

Nutritional Intake after Liver Transplant: Systematic Review and Meta-Analysis

Cardiovascular disease and its concurrent risk factors are prevalent after liver transplant (LT). Most of these risk factors are modifiable by diet. We aimed to synthesise the literature reporting the nutritional intake of liver transplant recipients (LTR) and the potential determinants of intake. We performed a systematic review and meta-analyses of studies published up until July 2021 reporting the nutritional intake of LTR. The pooled daily mean intakes were recorded as 1998 (95% CI 1889, 2108) kcal, 17 (17, 18)% energy from protein, 49 (48, 51)% energy from carbohydrates, 34 (33, 35)% energy from total fat, 10 (7, 13)% energy from saturated fat, and 20 (18, 21) g of fibre. The average fruit and vegetable intake ranged from 105 to 418 g/day. The length of time post-LT and the age and sex of the cohorts, as well as the continent and year of publication of each study, were sources of heterogeneity. Nine studies investigated the potential determinants of intake, time post-LT, gender and immunosuppression medication, with inconclusive results. Energy and protein requirements were not met in the first month post-transplant. After this point, energy intake was significantly higher and remained stable over time, with a high fat intake and low intake of fibre, fruits and vegetables. This suggests that LTR consume a high-energy, low-quality diet in the long term and do not adhere to the dietary guidelines for cardiovascular disease prevention.

DO THE IMMUNOSUPPRESSIVE DRUGS AFFECT THE HYPOTHALAMIC NUCLEI INVOLVED IN THE REGULATION OF FOOD INTAKE? AN EXPERIMENTAL STUDY

PURPOSE

Immunosuppressive drugs are essential for reducing the rejection risk in post-transplant patients, which is commonly associated with this procedure. However, side effects of those drugs on the hypothalamic nuclei involved in the food intake regulation, excessive weight gain, and also associated comorbidities are still unknown. The purpose of this study was to analyze possible changes in the neuronal morphology and cell density in the paraventricular nuclei, lateral hypothalamic area, dorsomedial nuclei, and ventromedial and arcuate nuclei in Wistar rats submitted to immunosuppressive treatment with tacrolimus (TAC) or mycophenolate mofetil (MMF).

METHODS

Adult male Wistar rats were randomly assigned to the following groups according to the oral treatment administered for 14 weeks: control, sham (placebo), TAC (1 mg/kg of weight), and MMF (30 mg/kg of weight). After treatment, the animals were sacrificed and their brains fixed for later histological staining. Subsequently, the slides were photodocumented for stereological analysis of the hypothalamic nuclei.

RESULTS

All experimental groups showed a weight gain throughout the study. There was no significant difference in neuronal density/number of cells in the hypothalamic nuclei between groups. Morphological changes were not detected in the hypothalamic neurons.

CONCLUSION

Treatments with immunosuppressants could not modify the morphological and cell density aspects of the hypothalamic nuclei during this supplementation period.

New-onset cardiovascular risk factors following liver transplantation: A cohort analysis in Singapore

INTRODUCTION

The aims of this study were to establish weight change, incidence of non-alcoholic fatty liver disease (NAFLD) and cardiovascular risk factors (CvRF) in liver transplant recipients (LTRs).

METHODS

Eighty-three patients whose mean (standard deviation [SD]) age was 55.6 (8.4) years (median follow-up 73 months) and who underwent their first liver transplantation (LT) at Singapore General Hospital between February 2006 and March 2017 were included in the study. Anthropometric, clinical and demographic data were collected retrospectively from patients' medical records. Diabetes mellitus (DM), hyperlipidaemia and hypertension were regarded as CvRF.

RESULTS

Compared to baseline, mean (SD) body weight decreased significantly at 1 month post-LT (60.8kg [11.9] versus 64.3kg [13.7], P<0.001). There was a gradual recovery of body weight thereafter, increasing significantly at year 2 (64.3kg [12.3] vs 61.5kg [13.7], P<0.001) until year 5 (66.9kg [12.4] vs 62.2kg [13.9], P<0.001), respectively. The prevalence of CvRF was significantly higher post-LT. NAFLD occurred in 25.3% of LTRs and it was significantly associated with post-LT DM and hyperlipidaemia.

CONCLUSION

CvRF increased significantly post-LT, and NAFLD occurred in 25.3% of LTRs. Body weight dropped drastically within the first month post-LT, which then returned to baseline level just before the end of first year. This novel finding suggests that nutritional intervention needs to be tailored and individualised, based on events and time from transplant. Although long-term obesity is a significant problem, aggressive oral or enteral nutritional supplements take precedence in the early and immediate post-LT period, while interventions targeted at metabolic syndrome become necessary after the first year.

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.

Metabolic syndrome following liver transplantation in nonalcoholic steatohepatitis

Metabolic syndrome is a major clinical disorder involving metabolic dysregulation characterized clinically with features of central obesity, insulin resistance (IR), type 2 diabetes, hypertension, and dyslipidemia. Metabolic syndrome is strongly associated with the rising prevalence nonalcoholic steatohepatitis, a leading indication for orthotopic liver transplantation in the Western world. The presence or recurrence of metabolic syndrome following liver transplantation can contribute to the development and recurrence of nonalcoholic fatty liver disease (NAFLD) in the liver allograft. In this review, we discuss the endogenous and exogenous drivers of post-transplant metabolic syndrome, role of chronic immunosuppression, and the prevalence and clinical significant of post-transplant metabolic syndrome on nonalcoholic steatohepatitis.

Metabolic Disorders After Liver Transplantation

Early after surgery, liver transplant (LT) recipients often develop weight gain due to an increase of caloric intake and fat mass (without recovery of muscle frame). This modification of body composition together with a negative metabolic impact of immunosuppressive drugs leads to a high prevalence of all the main metabolic disorders. Indeed, as expected, transplanted patients show a higher cardiovascular risk in comparison with general population. Notably, seeing the increase of mean age of transplanted population, metabolic disorders represent the true challenge for the transplant community. Considering the lack of evidences or clear indications about prevention, early diagnosis and treatment of metabolic disorders after LT, it would be mandatory to develop targeted further studies on this matter.

Pre-transplant diabetes predicts atherosclerotic vascular events and cardiovascular mortality in liver transplant recipients: a long-term follow-up study

Background Early after surgery, liver transplant (LT) recipients often develop weight gain. Metabolic disorders and cardiovascular disease represent main drivers of morbidity and mortality. Our aim was to identify predictors of atherosclerotic vascular events (AVE) and to assess the impact of AVE on the long-term outcome. Methods We retrospectively analyzed data from patients transplanted between 2000 and 2005 and followed-up in five Italian transplant clinics. Cox Regression analysis was performed to identify predictors of AVE, global mortality, and cardiovascular mortality. Survival analysis was performed using the Kaplan-Meier method. Results We analyzed data from 367 subjects during a median follow-up of 14 years. Thirty-seven post-LT AVE were registered. Patients with AVE more frequently showed pre-LT diabetes mellitus (DM) (48.6 vs 13.9%, p=0.000). In the post-LT period, patients with AVE satisfied criteria of metabolic syndrome in 83.8% vs. 36.7% of subjects without AVE (p=0.000). At multivariate analysis, pre-LT DM independently predicted AVE (HR 2.250, CI 4.848-10.440, p=0.038). Moreover, both pre-LT DM and AVE strongly predicted cardiovascular mortality (HR 5.418, CI 1.060-29.183, p=0.049, and HR 86.097, CI 9.510-779.480, p=0.000, respectively). Conclusions Pre-LT DM is the main risk factor for post-LT AVE. Pre-LT DM and post-LT AVE are strong, long-term predictors of cardiovascular mortality. Patients with pre-LT DM should obtain a personalized follow-up for prevention or early diagnosis of AVE.

Changes in Body Mass Index and Outcomes After Kidney Transplant: A Single-Center, Retrospective, Observational Study

OBJECTIVES

We aimed to describe changes in body mass index after kidney transplant and to assess how these changes influence long-term outcomes.

MATERIALS AND METHODS

Data were collected from kidney transplant recipients seen at our center between January 2007 and July 2016. Changes in body mass index over the posttransplant period were modeled using a generalized estimating equation, with changes calculated for each patient from pretransplant to 6 months posttransplant. Calculations were then categorized into 3 body mass index groups: stable (change of ± 1.5 kg/m² or less), reduced (reduction of > 1.5 kg/m²), and increased (increase of > 1.5 kg/m²). Outcomes among groups were compared.

RESULTS

Among 1344 total patients, the geometric mean pretransplant body mass index was 27.3 kg/m². This declined significantly (P < .001) to a geometric mean of 25.6 kg/m² at 1 month posttransplant, before increasing and stabilizing to pretransplant levels by 36 months (geometric mean body mass index of 27.2 kg/m² ; P = .522). Of 822 patients with body mass index measurements at 6 months, 303 had reduced, 388 had stable, and 131 had increased levels relative to pretransplant levels. On multivariate analyses, 12-month creatinine levels were significantly higher in the reduced cohort, with adjusted levels of 160.6 versus 135.0 μmol/L for the stable cohort. However, no significant associations were detected between 6-month body mass index changes and patient survival, graft survival, incidences of posttransplant diabetes and cancer, and a range of other clinical and histologic outcomes (all P > .05).

CONCLUSIONS

Our data demonstrated that body mass index was significantly reduced in the first month after kidney transplant before increasing to pretransplant levels during years 3 to 5. Furthermore, patients who retained decreased levels at 6 months had impaired graft function in long-term follow-up. These observations conflict with the existing literature and warrant further investigations.

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.

The Analysis of Food Intake in Patients with Cirrhosis Waiting for Liver Transplantation: A Neglected Step in the Nutritional Assessment

Patients with cirrhosis waiting for liver transplantation (LT) frequently present a nutritional disorder, which represents an independent predictor of morbidity and mortality before and after transplantation. Thus, a proper assessment of the food intake by using different methods, such as food records, food frequency questionnaires, and 24 h recall, should be deemed an important step of the nutritional management of these patients. The available published studies indicate that the daily food intake is inadequate in the majority of waitlisted patients. These findings were confirmed by our experience, showing that the daily intake of total calories, proteins and carbohydrates was inadequate in approximately 85–95% of patients, while that of lipids and simple carbohydrates was inadequate in almost 50% of them. These data highlight the need to implement an effective educational program provided by certified nutritionists or dieticians, who should work in close collaboration with the hepatologist to provide a nutritional intervention tailored to the individual patient requirements.

Posttransplant muscle mass measured by urinary creatinine excretion rate predicts long-term outcomes after liver transplantation

Long-term survival in orthotopic liver transplant (OLT) recipients remains impaired because of many contributing factors, including a low pretransplant muscle mass (or sarcopenia). However, influence of posttransplant muscle mass on survival is currently unknown. We hypothesized that posttransplant urinary creatinine excretion rate (CER), an established noninvasive marker of total body muscle mass, is associated with long-term survival after OLT. In a single-center cohort study of 382 adult OLT recipients, mean ± standard deviation CER at 1 year posttransplantation was 13.3 ± 3.7 mmol/24 h in men and 9.4 ± 2.6 mmol/24 h in women. During median follow-up for 9.8 y (interquartile range 6.4-15.0 y), 104 (27.2%) OLT recipients died and 44 (11.5%) developed graft failure. In Cox regression analyses, as continuous variable, low CER was associated with increased risk for mortality (HR = 0.43, 95% CI: 0.26-0.71, P = .001) and graft failure (HR = 0.42, 95% CI: 0.20-0.90, P = .03), independent of age, sex, and body surface area. Similarly, OLT recipients in the lowest tertile had an increased risk for mortality (HR = 2.69; 95% CI: 1.47-4.91, P = .001) and graft failure (HR = 2.77, 95% CI: 1.04-7.39, P = .04), compared to OLT recipients in the highest tertile. We conclude that 1 year posttransplant low total body muscle mass is associated with long-term risk of mortality and graft failure in OLT recipients.

De-novo nonalcoholic steatohepatitis is associated with long-term increased mortality in liver transplant recipients

OBJECTIVE

Patients who have undergone transplantation often develop metabolic syndrome (MetS) and de-novo nonalcoholic fatty liver disease (NAFLD). Our aim was to evaluate the impact of metabolic disease on cardiovascular and neoplastic risk and survival.

PATIENTS AND METHODS

Data from patients who underwent transplantation between 2000 and 2005 in two Italian transplant centers were analyzed. Cox regression analysis was carried out for predictors of de-novo NAFLD and nonalcoholic steatohepatitis (NASH), cardiovascular events, de-novo extrahepatic cancers, and survival. Survival analysis was completed using the Kaplan-Meier method. A P value less than 0.05 was considered significant for all tests.

RESULTS

De-novo NAFLD was found in one-fifth of 194 patients. Patients with de-novo NAFLD fulfilled the criteria of MetS in 74.4% of cases, while patients without de-novo NAFLD in 29.8% (P=0.000). On multivariate analysis, MetS correlated independently with de-novo NAFLD and this emerged as an independent predictor of cardiovascular events and as a relevant risk factor for solid extrahepatic cancer. Data on smoking habits, which represent a consolidated risk factor for cardiovascular events and cancer in both the general population and patients who have undergone transplantation, are not available. In the subset of histologically proven NASH, it was the strongest predictor of long-term survival (hazard ratio=4.133, 95% confidence interval: 1.385-12.331, P=0.011).

CONCLUSION

Post-transplant NAFLD represented a strong risk factor for cardiovascular atherosclerotic disease and solid extrahepatic cancer, whereas de novo histologically proven NASH was an independent predictor of long-term mortality.

Nutritional Therapy in Liver Transplantation

Protein-energy malnourishment is commonly encountered in patients with end-stage liver disease who undergo liver transplantation. Malnutrition may further increase morbidity, mortality and costs in the post-transplantation setting. The importance of carefully assessing the nutritional status during the work-up of patients who are candidates for liver replacement is widely recognized. The metabolic abnormalities induced by liver failure render the conventional assessment of nutritional status to be challenging. Preoperative loss of skeletal muscle mass, namely, sarcopenia, has a significant detrimental impact on post-transplant outcomes. It is essential to provide sufficient nutritional support during all phases of liver transplantation. Oral nutrition is preferred, but tube enteral nutrition may be required to provide the needed energy intake. Herein, the latest currently employed perioperative nutritional interventions in liver transplant recipients are thoroughly illustrated including synbiotics, micronutrients, branched-chain amino acid supplementation, immunonutrition formulas, fluid and electrolyte balance, the offering of nocturnal meals, dietary counselling, exercise and rehabilitation.

Resting and Exercise Energy Metabolism After Liver Transplantation for Nonalcoholic Steatohepatitis

Background

Nonalcoholic steatohepatitis (NASH) is a leading indication for liver transplantation (LT). We hypothesized that weight gain after LT may be exacerbated by reduced metabolic rates due to the LT procedure, particularly during exercise. We aimed to compare resting and exercise energy expenditure between patients transplanted for NASH and nontransplant nonalcoholic fatty liver disease (NAFLD) subjects.

Methods

NASH LT recipients (>1-year post, n = 14) and NAFLD controls (n = 13) underwent analysis of body composition, resting energy expenditure (REE), and exercise energy expenditure (VO_2max), the latter using a ramped-Bruce protocol assessed by expired gas analysis and peak heart rate.

Results

Participants were mean 61.5 ± 7.9 years, 48.1% men, and 66.7% white. Baseline comorbidities were similar between groups. Among men, mean REE adjusted for total (17.7 vs 18.8, P = 0.87) and lean body mass (23.5 vs 26.9, P = 0.26), as well as VO₂ (20.1 vs 23.9, P = 0.29), was lower in NASH LT recipients compared with NAFLD controls, respectively, although not statistically significant. However, female NASH LT recipients had significantly lower mean REE than NAFLD controls when adjusted for total (14.2 vs 18.9, P = 0.01) and lean body mass (19.3 vs 26.5, P = 0.002), as well as significantly lower VO_2max (14.4 vs 20.6, P = 0.017).

Conclusions

NASH LT recipients, particularly women, have lower REE and exercise energy expenditure compared with nontransplant NAFLD patients. More aggressive diet and exercise programs for post-LT NASH recipients to account for reduced resting and exercise metabolic rates may attenuate weight gain in this vulnerable population.

Hepatic gene therapy rescues high-fat diet responses in circadian Clock mutant mice

OBJECTIVE

Circadian Clock gene mutant mice show dampened 24-h feeding rhythms and an increased sensitivity to high-fat diet (HFD) feeding. Restricting HFD access to the dark phase counteracts its obesogenic effect in wild-type mice. The extent to which altered feeding rhythms are causative for the obesogenic phenotype of Clock mutant mice, however, remains unknown.

METHODS

Metabolic parameters of wild-type (WT) and ClockΔ19 mutant mice (MT) were investigated under ad libitum and nighttime restricted HFD feeding. Liver circadian clock function was partially rescued by hydrodynamic tail vein delivery of WT-Clock DNA vectors in mutant mice and transcriptional, metabolic, endocrine and behavioral rhythms studied.

RESULTS

Nighttime-restricted feeding restored food intake, but not body weight regulation in MT mice under HFD, suggesting Clock-dependent metabolic dysregulation downstream of circadian appetite control. Liver-directed Clock gene therapy partially restored liver circadian oscillator function and transcriptome regulation without affecting centrally controlled circadian behaviors. Under HFD, MT mice with partially restored liver clock function (MT-LR) showed normalized body weight gain, rescued 24-h food intake rhythms, and WT-like energy expenditure. This was associated with decreased nighttime leptin and daytime ghrelin levels, reduced hepatic lipid accumulation, and improved glucose tolerance. Transcriptome analysis revealed that hepatic Clock rescue in MT mice affected a range of metabolic pathways.

CONCLUSION

Liver Clock gene therapy improves resistance against HFD-induced metabolic impairments in mice with circadian clock disruption. Restoring or stabilizing liver clock function might be a promising target for therapeutic interventions in obesity and metabolic disorders.

ESTIMATING BASAL ENERGY EXPENDITURE IN LIVER TRANSPLANT RECIPIENTS: THE VALUE OF THE HARRIS-BENEDICT EQUATION

Background:

Reliable measurement of basal energy expenditure (BEE) in liver transplant (LT) recipients is necessary for adapting energy requirements, improving nutritional status and preventing weight gain. Indirect calorimetry (IC) is the gold standard for measuring BEE. However, BEE may be estimated through alternative methods, including electrical bioimpedance (BI), Harris-Benedict Equation (HBE), and Mifflin-St. Jeor Equation (MSJ) that carry easier applicability and lower cost.

Aim:

To determine which of the three alternative methods for BEE estimation (HBE, BI and MSJ) would provide most reliable BEE estimation in LT recipients.

Methods:

Prospective cross-sectional study including dyslipidemic LT recipients in follow-up at a 735-bed tertiary referral university hospital. Comparisons of BEE measured through IC to BEE estimated through each of the three alternative methods (HBE, BI and MSJ) were performed using Bland-Altman method and Wilcoxon Rank Sum test.

Results:

Forty-five patients were included, aged 58±10 years. BEE measured using IC was 1664±319 kcal for males, and 1409±221 kcal for females. Average difference between BEE measured by IC (1534±300 kcal) and BI (1584±377 kcal) was +50 kcal (p=0.0384). Average difference between the BEE measured using IC (1534±300 kcal) and MSJ (1479.6±375 kcal) was -55 kcal (p=0.16). Average difference between BEE values measured by IC (1534±300 kcal) and HBE (1521±283 kcal) was -13 kcal (p=0.326). Difference between BEE estimated through IC and HBE was less than 100 kcal for 39 of all 43patients.

Conclusions:

Among the three alternative methods, HBE was the most reliable for estimating BEE in LT recipients.

Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome after Liver Transplant

Liver transplant is the unique curative therapy for patients with acute liver failure or end-stage liver disease, with or without hepatocellular carcinoma. Increase of body weight, onset of insulin resistance and drug-induced alterations of metabolism are reported in liver transplant recipients. In this context, post-transplant diabetes mellitus, hyperlipidemia, and arterial hypertension can be often diagnosed. Multifactorial illnesses occurring in the post-transplant period represent significant causes of morbidity and mortality. This is especially true for metabolic syndrome. Non-alcoholic steatosis and steatohepatitis are hepatic manifestations of metabolic syndrome and after liver transplant both recurrent and de novo steatosis can be found. Usually, post-transplant steatosis shows an indolent outcome with few cases of fibrosis progression. However, in the post-transplant setting, both metabolic syndrome and steatosis might play a key role in the stratification of morbidity and mortality risk, being commonly associated with cardiovascular disease. The single components of metabolic syndrome can be treated with targeted drugs while lifestyle intervention is the only reasonable therapeutic approach for transplant patients with non-alcoholic steatosis or steatohepatitis.

Changes in nutritional status after liver transplantation

Chronic liver disease has an important effect on nutritional status, and malnourishment is almost universally present in patients with end-stage liver disease who undergo liver transplantation. During recent decades, a trend has been reported that shows an increase in number of patients with end-stage liver disease and obesity in developed countries. The importance of carefully assessing the nutritional status during the work-up of patients who are candidates for liver replacement is widely recognised. Cirrhotic patients with depleted lean body mass (sarcopenia) and fat deposits have an increased surgical risk; malnutrition may further impact morbidity, mortality and costs in the post-transplantation setting. After transplantation and liver function is restored, many metabolic alterations are corrected, dietary intake is progressively normalised, and lifestyle changes may improve physical activity. Few studies have examined the modifications in body composition that occur in liver recipients. During the first 12 mo, the fat mass progressively increases in those patients who had previously depleted body mass, and the muscle mass recovery is subtle and non-significant by the end of the first year. In some patients, unregulated weight gain may lead to obesity and may promote metabolic disorders in the long term. Careful monitoring of nutritional changes will help identify the patients who are at risk for malnutrition or over-weight after liver transplantation. Physical and nutritional interventions must be investigated to evaluate their potential beneficial effect on body composition and muscle function after liver transplantation.

Overweight in liver transplant recipients

This review aims to describe the incidence and prevalence of overweight and obesity after liver transplantation and the consequences associated with it. Literature review consultation was conducted in Medline / PubMed, SciELO, EMBASE and LILACS, with the combination of the following keywords: liver transplantation, overweight, obesity, weight gain. Overweight is incident on more than 60% of patients undergoing liver transplantation and obesity rates exceed 20% in the first year after surgery, during which occurs the largest relative weight gain. Studies have shown that between 60% and 70% of patients undergoing liver transplantation are overweight after the third year, 90% with abdominal obesity. Associated factors are, among others, advanced age, family history of overweight and excess weight prior to liver disease. The contribution of immunosuppressive medication remains controversial. Some of the consequences of overweight are liver steatosis, steatohepatitis, diabetes mellitus, hypertension, dyslipidemia, cardiovascular disease and death.

Obesity and organ transplantation: successes, failures, and opportunities

The increasing rate of societal obesity is also affecting the transplant world through obesity in candidates and donors as well as its posttransplant repercussions. Being overweight and obese has been shown to have significant effects on both short- and long-term complications as well as patient and graft survival. However, much of the comorbidity can be controlled or prevented with careful patient selection and aggressive management. A team approach to managing obesity and its comorbidities both pre- and posttransplant is essential for successful transplant outcomes. Complicating understanding the results of obesity research is the inclusion different weight categories, use of listing vs transplant weights, patient populations large enough for statistical power, and changes in transplant management, especially immunosuppression protocols, anti-infection protocols, and operative techniques. Much more research is needed regarding many elements, including safe weight loss before transplantation, prevention of weight gain after transplant, genomic influences, and the role of bariatric surgery in the transplant process.

Resting energy expenditure, body composition, and dietary intake: a longitudinal study before and after liver transplantation

BACKGROUND

The loss of hepatic innervations after liver transplantation (LTx) might affect the energy metabolism of the patients. The aim of this study was to assess the resting energy expenditure (REE), body composition, and dietary intake before and during the first year after the LTx.

METHODS

The REE was measured by indirect calorimetry. Nutritional status was assessed by anthropometric assessment, bioimpedance, handgrip strength, and dietary intake (before and 30, 90, 180, 270, and 370 days after LTx). Social, clinical, and nutritional variables were assessed as being potentially associated with REE or hypermetabolism and hypometabolism after LTx.

RESULTS

Seventeen patients were included. REE was elevated at 30 days and reduced at the end of the study (P<0.05). Hypermetabolism/hypometabolism were low but present at the end of the study (11.8% of each). Increases in body weight and fat mass were observed (P<0.05). Handgrip strength and phase angle improved after LTx (P<0.05). Energy balance was positive at all times after LTx, and an increase in fat intake occurred (P<0.05). After multivariate analyses (P<0.05), the REE before transplantation and triceps skinfold thickness were positively associated and the cumulative dose of prednisone was negatively associated with REE after LTx. The presence of hypermetabolism was significantly associated with the presence of hypermetabolism before LTx and the cumulative dose of prednisone. Percentage of fat intake and fat mass before LTx was associated with hypometabolism.

CONCLUSION

Some potential modifiable factors are related to resting energy metabolism in patients undergoing LTx. Adequate and individualized nutritional guidance should be started before LTx.

Prevalence and risk factors for obesity after liver transplantation: a single-center experience

BACKGROUND

The study of weight gain after transplantation and its associated factors is necessary to propose strategies to prevent and treat this problem.

OBJECTIVES

This study aims to investigate factors affecting the development of obesity after liver transplantation (LTx).

PATIENTS AND METHODS

Medical records of 343 liver transplantation cases, which were followed between January 2001 and January 2010 at Dokuz Eylul University, were retrospectively analyzed. Patient pre-liver transplantation height, body weight, body mass index (BMI) measurements, as well as changes in body weight at the beginning, 6 months, 12 months, and 5 years post-transplantation were observed. BMI measurements with records of immunosuppressive therapies were obtained.

RESULTS

The study was carried out with the records of 226 patients. 151 patients (66.8%) were male; 75 (33.2%) were female. The mean age was 46.19 ± 10.2 years. 123 of these liver transplants were performed from living donors, while 103 were from cadaveric donors. The causes of liver transplantation were hepatitis D virus (HDV) infection (28%), hepatitis B virus (HBV) infection (24%), hepatitis C virus (HCV) infection (24%), alcoholic liver disease (9%), cryptogenic liver disease (9%), autoimmune hepatitis (4%), and other (2%). In this study, the prevalence of obesity was 21% at the end of the second year, decreasing to 14% by the end of the fifth year. The mean BMI gradually increased during the follow-ups, reaching 25.1 kg/m² and 26 kg/m² six months after liver transplantation and at the end of the first year, respectively (P < 0.002). Obesity developed in 18.2% of post-transplant patients who were receiving a calcineurin inhibitor (CNI). Regarding the development of obesity after transplantation, no statistically significant difference was found between patients using cyclosporine (CsA) and tacrolimus (TAC) (P = 0.07). Six months after liver transplantation, the mean body weight gain in the groups receiving steroids and not receiving steroids were 4.71 kg and 2.7 kg, respectively (P = 0.03). In the post-transplant period, there was no significant difference in patients who had received TAC and CsA for development of diabetes mellitus (DM), hypertension (HT), or hyperlipidemia (HL) (P = 0.30).

CONCLUSIONS

Obesity prevalence before and after liver transplantation was comparable. Education of obese patients prior to surgery and recommendation of medical nutrition therapy should be appropriate. Similar medical care for the non-obese subjects could prevent increase in obesity prevalence. Non-corticosteroid immunosuppressive agents had no significant effect on the development of weight gain and obesity. Avoiding the use of long-term steroid therapy and obesity education are the key measures for preventing obesity after liver transplantation.

Weight gain in long-term survivors of kidney or liver transplantation--another paradigm of sarcopenic obesity?

OBJECTIVE

Obesity in transplant recipients is a frequent phenomenon but data from body composition analyses in long-term survivors are limited. Body composition and energy metabolism were studied in patients after liver (LTX) and kidney (KTX) transplantation and patients with liver cirrhosis (LCI) or on chronic hemodialysis (HD) and compared to healthy controls.

METHODS

In 42 patients 50.0 mo (median; range 17.1-100.6) after LTX and 30 patients 93.0 mo (31.2-180.1) after KTX as wells as in LCI (n = 39) or HD (n = 10) patients mid-arm muscle and fat area, body cell mass, and phase angle (bioimpedance analysis), and resting energy expenditure (indirect calorimetry, REE(CALO)) were measured.

RESULTS

Obesity was more prevalent in LTX (17%) than LCI (3%) and in KTX (27%) than in HD (10%). In LTX and KTX, phase angle was higher than in end-stage disease (LTX 5.6° [4.1-7.2] versus LCI 4.4° [2.9-7.3], P < 0.001; KTX 5.9° [4.4-8.7] versus HD 4.3° [2.9-6.8]) but was lower in all patient groups than in controls (7.1°; 4.6-8.9; P < 0.001). In LCI and HD REE(CALO) was higher than predicted, while in LTX and KTX REE(CALO) was not different from predicted REE.

CONCLUSIONS

Despite excellent graft function, many long-term LTX or KTX survivors exhibit a phenotype of sarcopenic obesity with increased fat but low muscle mass. This abnormal body composition is observed despite normalization of the hypermetabolism found in chronic disease and cannot be explained by overeating. The role of appropriate nutrition and physiotherapy after transplantation merits further investigation.

Body composition and overweight of liver transplant recipients

BACKGROUND

Overweight is often used as a description after liver transplantation (LTx), but studies on body composition of patients submitted to LTx have only been devoted to early postoperative periods; there is little information regarding abdominal obesity after LTx. The aim of this study was to assess body composition, body mass index (BMI), and waist circumference and verify the prevalence and risk factors for excessive weight, obesity, and abdominal obesity in long-term survivors of LTx.

METHODS

Post-LTx patients with at least 1 year post-LTx were assessed for their body composition (by bioimpedance), BMI, and waist circumference. Demographic, socioeconomic, lifestyle, and clinical and dietetic variables were collected to assess risk factors using linear and logistic regression analyses.

RESULTS

We evaluated 143 patients (51±13 years; 59.4% male; median time since LTx: 4 years). The majority of patients had excessive weight, considering BMI, (58.1%). Considering body composition, 69.9% of patients were overweight and 37.8% obese. Some degree of abdominal obesity was seen in 88% of patients. Independent risk factors for overweight, obesity, and abdominal obesity after LTx included greater BMI before liver disease, weight gain since LTx, family history of overweight, smoking, working, being married, having less time since transplantation, a lower calcium intake, and less sleeping hours.

CONCLUSIONS

The majority of patients are overweight or obese after LTx, and many of the associated risk factors are modifiable. Thus, patients, especially those who already have identified risk factors for overweight and obesity, undergoing LTx should be encouraged to engage in lifestyle changes early.

Long-term management of the liver transplant recipient: pearls for the practicing gastroenterologist

Liver transplantation is becoming more common and patients are surviving longer after transplantation. Special care must be paid to the long-term management of these patients because they are at increased risk for medical problems, malignancies, and adverse effects from immunosuppression. A stable and continuing relationship must be developed between the physician and the patient to optimize the long-term outcomes for these individuals.

Determinants of overweight and obesity in lung transplant recipients

BACKGROUND

Obesity-related diseases have been shown to affect post-lung transplantation survival. An estimated 30% of lung transplant recipients develop overweight.

OBJECTIVE

The aim of this study was to examine the possible determinants of large increases in weight after lung transplantation. The contribution of physical activity, food intake, and resting energy expenditure was examined in lung transplant recipients.

METHODS

In this cross-sectional study 21 overweight lung transplant recipients (11 men, mean age 57 ± 7 years; BMI 30 ± 3) and 21 normal-weight lung transplant recipients (11 men, mean age 56 ± 5 years; BMI 22 ± 3) were matched for disease, gender, age, prescribed medication, and time since lung transplantation. Physical activity was measured by a pedometer and a questionnaire; resting energy expenditure was measured by the ventilated-hood technique, and daily food intake by a dietician. Additionally, fat-free mass, lower-body strength, and fatigue were measured.

RESULTS

The overweight lung transplant recipients had a significantly lower number of steps per day (4,686 ± 3,266 vs. 7,524 ± 3,448 steps/day, p = 0.01) and a lower fat-free mass (64 ± 9 vs. 75 ± 6%, p < 0.05) compared to normal-weight recipients. Obese subjects had a lower percentage of predicted resting energy expenditure level compared to normal-weight recipients (90 ± 14 vs. 100 ± 14% predicted, p = 0.04).

CONCLUSION

Our data suggest that overweight in lung transplant recipients is associated with a lower fat-free mass and lower levels of physical activity and resting energy expenditure compared to normal-weight recipients.

Metabolic syndrome and its components after liver transplantation: incidence, prevalence, risk factors, and implications

Metabolic syndrome is defined as the mutual existence of obesity, impaired fasting glucose levels, insulin resistance, hypertension, and dyslipidemia. After liver transplantation, patients typically develop these disorders, and even though there has been minimal research focused on the chronic impact of this syndrome on post-liver transplant patients, studies point to an association with major vascular events and fibrosis. The aim of the current work is to review data on the incidence, prevalence, risk factors, and implications of metabolic syndrome and its components in patients who have undergone liver transplantation.

Physical fitness, fatigue, and quality of life after liver transplantation

Fatigue is often experienced after liver transplantation. The aims of this cross-sectional study were to assess physical fitness (cardiorespiratory fitness, neuromuscular fitness, body composition) in liver transplant recipients and to explore whether physical fitness is related to severity of fatigue. In addition, we explored the relationship between physical fitness and health-related quality of life. Included were 18 patients 1-5 years after transplantation (aged 48.0 +/- 11.8 years) with varying severity of fatigue. Peak oxygen uptake during cycle ergometry, 6-min walk distance, isokinetic muscle strength of the knee extensors, body mass index, waist circumference, skinfold thickness, severity of fatigue, and health-related quality of life were measured. Cardiorespiratory fitness in the liver transplant recipients was on average 16-34% lower than normative values (P Collapse

Key Words

• liver transplantation
• fatigue
• peak oxygen uptake
• isokinetic muscle strength
• body composition

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MESH Headings

• Adult
• Body Composition/physiology
• Cardiovascular Physiological Phenomena
• Cross-Sectional Studies
• Fatigue/physiopathology
• Female
• Humans
• Liver Transplantation/physiology
• Male
• Middle Aged
• Muscle Strength/physiology
• Oxygen Consumption/physiology
• Physical Fitness/physiology
• Quality of Life
• Respiratory Physiological Phenomena
• Severity of Illness Index

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Affiliation(s)

Berbke T J van Ginneken Department of Rehabilitation Medicine, Erasmus University Medical Center Rotterdam, The Netherlands.
Rita J G van den Berg-Emons
Geert Kazemier
Herold J Metselaar
Hugo W Tilanus
Henk J Stam

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Changes in weight during the first year after kidney transplantation

CONTEXT

Obesity frequently occurs following kidney transplantation and is of concern because of the associated risk for cardiovascular complications.

OBJECTIVE

To examine weight gain over the first year after kidney transplantation to determine associations with gender, ethnicity, and cardiovascular risk factors.

DESIGN

A retrospective analysis was completed on patients who had received transplants between January 1998 and January 2002 and who had matching baseline and 1-year follow-up data and a functional graft.

PARTICIPANTS

The sample consisted of 171 recipients (33% women, 58% African Americans, and 39% whites) with a mean age of 44 +/- 12.2 years.

MAIN OUTCOME MEASURES

Outcome measures included fasting blood sugar, triglycerides, creatinine levels, and body mass index categorized as normal, overweight, or obese.

RESULTS

The total group showed a significant increase in mean weight (6.2 +/- 10.7 kg) and body mass index (2.1 +/- 3.8). Although equivalent at baseline, by 1 year after transplantation there were significantly more obese than normal-weight recipients, regardless of gender or ethnicity, with African Americans increasing more than whites and women more than men. At baseline, those characterized as obese versus normal weight were older (47 vs. 41 years; P < .05), with a higher fasting blood sugar. At 1 year, differences in age and fasting blood sugar disappeared; however, the obese group had higher triglycerides (235 vs. 165, P = .01).

CONCLUSIONS

Weight gain after transplantation was not explained by demographic and clinical factors. We speculate additional variables such as genetic factors influence weight gain and warrant study.

Transplanted liver: consequences of denervation for liver functions

Following liver transplantation, all hepatic nerves are transected; thus, liver allografts are completely isolated from neural control of their hosts. Despite this absolute denervation, liver allograft function does not appear to be significantly impaired after successful transplantation. In experimental animal models, hepatic denervation has no major effects on bile acid production and biotransformation, while it increases blood pressure and salt retention; decreases the number of hepatic progenitor cells, cholangiocyte proliferation, and liver regeneration; and influences the hepatic microcirculation, diet behavior, and glycemic control. In humans, hepatic denervation after liver transplantation has no major deleterious effects on bile secretion, liver regeneration, and hepatic blood flow. Insulin resistance and postprandial hyperglycemia, changes in ingestion behavior, and reduced stimulation of hepatic progenitor cells in the canals of Hering are the major side effects of absent liver innervation. Despite these abnormalities, patients can lead a new life with improved quality of life.

Weight gain after lung transplantation

BACKGROUND

Weight gain is frequently observed after lung transplantation, but the magnitude, predictors and implications of weight gain after lung transplant are unknown.

METHODS

This retrospective cohort study included 826 lung transplant recipients randomly selected from 12 international transplant centers. We included adult patients with available weight data at baseline and 1 year post-transplant. We examined demographic and clinical predictors of first year weight gain using a multiple linear regression model (n = 579) with percent weight change as the dependent variable. To study the association between first year weight gain and subsequent survival, we performed a Cox proportional hazards analysis. p < 0.05 was considered statistically significant.

RESULTS

The median weight change was 10% (range -32% to 84%). On multi-variate analysis, increasing age and prolonged mechanical ventilation were inversely associated with weight gain; obstructive disease, interstitial disease and increasing ischemic time were positively associated with weight gain. Increasing baseline weight was negatively associated with weight gain in patients with obstructive and interstitial disease. The model accounted for 14% of the variance in weight gain. Patients with weight gain above the median had better subsequent survival (adjusted hazard ratio 0.61, 95% confidence interval 0.41 to 0.90). Infection was a more common cause of death in these patients, whereas malignant deaths were more frequent in patients with below-median weight gain.

CONCLUSIONS

Substantial weight gain occurs in the first year after lung transplantation. The predictors of weight gain may be used to target high-risk patients for early intervention. Higher weight gain is associated with better subsequent survival.

Cachexia in liver cirrhosis

Patients with chronic liver disease exhibit a progressive loss of fat and muscle mass leading to mixed protein-energy malnutrition. The severe loss of muscle mass and body cell mass have convincingly been shown to carry a grave prognosis. Cachexia is likely to progress due to increased requirements as a consequence of hypermetabolism on the one hand and reduced volitional food intake and malabsorption on the other. Hypermetabolism may be mediated by factors such as frequent episodes of endotoxinemia, an activation of the inflammatory cytokine and/or the beta-adrenergic system. Some of these factors may also be responsible for reduced appetite. Obviously, these mechanisms may also be operative in other disease entities but clearly, portal hypertension and portosystemic shunting pose the cirrhotic patient at a particular risk for such disturbances including that of malabsorption. Apart from the established value of providing sufficient nutritious substrate to meet requirements the use of beta-adrenergic blocking agents and endotoxinemia lowering strategies seem worthwhile options that merit further clinical evaluation.