Pre-transplant Sarcopenic Obesity Worsens the Survival After Liver Transplantation: A Meta-Analysis and a Systematic Review

Sarcopenic obesity and health outcomes: An umbrella review of systematic reviews with meta-analysis

Many studies support the idea that sarcopenic obesity (SO) could be considered a potential risk factor for negative health outcomes. These results have been inconsistent, and no umbrella reviews exist regarding this topic. Several databases until November 2023 were searched for systematic reviews with meta-analysis of observational studies (cross-sectional, case-control and prospective). For each association, random-effects summary effect sizes with correspondent 95% confidence intervals (CIs) were evaluated using the GRADE tool. Among the 213 papers initially screened, nine systematic reviews with meta-analysis were included, for a total of 384 710 participants. In cross-sectional and case-control studies, 30 different outcomes were analysed, and 18 were statistically significant. In any population addressed in cross-sectional and case-control studies, compared with non-SO, SO increased the prevalence of cognitive impairment (k = 3; odds ratio [OR] = 3.46; 95% CI: 2.24-5.32; high certainty of evidence), coronary artery disease (k = 2; OR = 2.48; 95% CI: 1.85-3.31) and dyslipidaemia (k = 3; OR = 2.50; 95% CI: 1.51-4.15). When compared with sarcopenia or obesity, the results were conflicting. In prospective studies, the association between SO-compared with non-SO-and other negative outcomes was supported by low/very low certainty of evidence and limited to a few conditions. Besides, no comparison with sarcopenia or obesity was provided. Finally, only a few studies have considered muscle function/physical performance in the diagnostic workup. SO could be considered a risk factor only for a few conditions, with the literature mainly based on cross-sectional and case-control studies. Future studies with clear definitions of SO are needed for quantifying the importance of SO-particularly when compared with the presence of only sarcopenia or obesity-and the weight of muscle function/physical performance in its definition.

Sarcopenic obesity in patients awaiting liver transplant: Unique challenges for nutritional recommendations

Sarcopenic obesity increases the risk of mortality in patients with liver disease awaiting liver transplantation and in the post-transplant period. Nutrition recommendations for individuals with sarcopenia differ from recommendations for patients with obesity or sarcopenic obesity. While these nutrition guidelines have been established in non-cirrhotic patients, established guidelines for liver transplant candidates with sarcopenic obesity are lacking. In this paper, we review existing literature on sarcopenic obesity in patients with chronic liver disease and address opportunities to improve nutritional counseling in patients awaiting liver transplantation.

[The role of the musculoadipose status in the assessment of the risk profile before liver transplantation]

Sarcopenia and sarcopenic obesity worsen the prognosis after liver transplantation; however, the assessment of body composition is not yet considered in the evaluation prior to liver transplantation to estimate the risk profile of the recipient. Prehabilitation, which includes the nutritional supplementation and physiotherapy, represents a recent focus of interest in clinical transplantation research. This article gives an overview of the recent knowledge about the role of the musculoadipose status and the available methods for the estimation in the assessment of the recipient's risk profile.

Sarcopenic obesity may predict worse liver regeneration after right graft living donor liver transplantation

Sarcopenic obesity impairs the outcome after liver transplantation. The effect of this on liver regeneration has not yet been studied. The aim of this study was to evaluate the potential effect of body composition changes on liver volume gain after living donor liver transplantation. We observed liver regeneration in 100 patients who underwent living donor liver transplantation using right lobe grafts (Segments V-VIII). Liver volumetry and body composition analysis were performed based on CT images with special software. The gain of liver volume was calculated between 2 points in time considering the absolute and percentage values: before surgery and early after surgery, with a median time of 10 days. Pearson's correlation and multivariate analysis using stepwise multiple regression were used to examine the potential correlation between body composition and liver volume gain. The liver volume increase was significantly negatively correlated with adipose tissue in the body stem ( r = -0.4, p < 0.001) and positively correlated with psoas mass ( r = 0.24, p = 0.02). These results correspond with those of the multiple regression analysis, which indicated adipose tissue (ß = -1.0, p < 0.001) and psoas mass (ß = 0.12, p < 0.001). The presence of malignancy as an indication for liver transplantation was another significant independent factor negatively affecting liver growth (ß = -13.1, p = 0.046). Sarcopenic obesity predicts an impaired liver volume increase after living donation. This could worsen the postoperative outcome. The role of alimentary interventions and exercises in improving body composition and thus postoperative outcome should be evaluated through prospective interventional studies.

Childhood Obesity: Insight into Kidney Involvement

This review examines the impact of childhood obesity on the kidney from an epidemiological, pathogenetic, clinical, and pathological perspective, with the aim of providing pediatricians and nephrologists with the most current data on this topic. The prevalence of childhood obesity and chronic kidney disease (CKD) is steadily increasing worldwide, reaching epidemic proportions. While the impact of obesity in children with CKD is less pronounced than in adults, recent studies suggest a similar trend in the child population. This is likely due to the significant association between obesity and the two leading causes of end-stage renal disease (ESRD): diabetes mellitus (DM) and hypertension. Obesity is a complex, systemic disease that reflects interactions between environmental and genetic factors. A key mechanism of kidney damage is related to metabolic syndrome and insulin resistance. Therefore, we can speculate about an adipose tissue-kidney axis in which neurohormonal and immunological mechanisms exacerbate complications resulting from obesity. Adipose tissue, now recognized as an endocrine organ, secretes cytokines called adipokines that may induce adaptive or maladaptive responses in renal cells, leading to kidney fibrosis. The impact of obesity on kidney transplant-related outcomes for both donors and recipients is also significant, making stringent preventive measures critical in the pre- and post-transplant phases. The challenge lies in identifying renal involvement as early as possible, as it is often completely asymptomatic and not detectable through common markers of kidney function. Ongoing research into innovative technologies, such as proteomics and metabolomics, aims to identify new biomarkers and is constantly evolving. Many aspects of pediatric disease progression in the population of children with obesity still require clarification. However, the latest scientific evidence in the field of nephrology offers glimpses into various new perspectives, such as genetic factors, comorbidities, and novel biomarkers. Investigating these aspects early could potentially improve the prognosis of these young patients through new diagnostic and therapeutic strategies. Hence, the aim of this review is to provide a comprehensive exploration of the pathogenetic mechanisms and prevalent pathological patterns of kidney damage observed in children with obesity.

Malnutrition in solid organ transplant patients: A review of the literature

Screening for malnutrition is of vital importance for solid organ transplant candidates to optimize nutrition status before transplant, to improve clinical outcomes and to inform selection committees of nutritional contraindications and risks. There are multiple criteria and screening tools available for determining malnutrition diagnosis and risk. Registered Dietitian Nutritionists use these tools for nutrition assessments to quantify the severity of malnutrition, provide patient-centered interventions, and monitor progression. Many transplant centers in the United States utilize the American Society of Parenteral and Enteral Nutrition and the Academy of Nutrition and Dietetics' Adult Malnutrition Criteria, though there is limited research using these criteria specifically in the transplant population. Malnutrition, utilizing other diagnostic and screening tools, has been associated with important complications, including longer length of hospital stay, increased mortality, decreased quality of life, worsened end-stage organ progression, and decreased functional status. Malnutrition typically results from sarcopenia and cachexia, and can ultimately lead to frailty, causing further negative impacts on transplant outcomes. This literature review summarizes the current research on malnutrition in solid organ transplant candidates and provides recommendations for future research and current practice implications.

Impact of sarcopenia and sarcopenic obesity on survival in patients with primary liver cancer: a systematic review and meta-analysis

Background

Sarcopenia and sarcopenic obesity are associated with an increased possibility of adverse clinical outcomes; however, the effects of sarcopenia and sarcopenic obesity on patients with primary liver cancer remain controversial. Therefore, the present study aimed to determine the impact of sarcopenia and sarcopenic obesity on survival in patients with primary liver cancer.

Methods

We searched studies published in English in PubMed, Embase, Web of Science, and Cochrane Library databases up to 13 November 2022. Cohort studies that reported the association among sarcopenia, sarcopenic obesity, and patient survival were included.

Results

A total of 64 cohort studies with data on 11,970 patients with primary liver cancer were included in the meta-analysis. Sarcopenia was associated with poor overall survival in patients with primary liver cancer [adjusted hazard ratio (HR) 2.11, 95% confidence interval (CI): 1.89-2.36, P < 0.0001], with similar findings for sarcopenic obesity (adjusted HR: 2.87, 95% CI: 2.23-3.70, P < 0.0001). Sarcopenia was also associated with poor overall survival across the subgroups analyzed by ethnicity, type of liver cancer, treatment modalities, method used to define sarcopenia, and etiology of liver cancer. We also found a negative correlation among sarcopenia, sarcopenic obesity, and recurrence-free/disease-free survival (adjusted HR: 1.73, 95% CI: 1.50-1.99, P < 0.001; adjusted HR: 2.28, 95% CI: 1.54-3.35, P < 0.001, respectively).

Conclusion

Sarcopenia and sarcopenic obesity were significantly associated with poor overall survival and recurrence-free/disease-free survival in patients with primary liver cancer.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=378433, PROSPERO [42022378433].

Nutritional Management of a Liver Transplant Candidate

Nearly two-thirds of patients with cirrhosis suffer from malnutrition resulting from multiple contributory factors such as poor intake, accelerated starvation, catabolic milieu, and anabolic resistance. Nutritional assessment and optimization are integral to adequate management of a liver transplant (LT) candidate. A detailed nutritional assessment should be done at baseline in all potential transplant candidates with periodic reassessments. Sarcopenia is defined as a reduction in muscle mass, function, and/or performance. Skeletal muscle index at 3rd lumbar vertebra determined by computed tomography is the most objective tool to assess muscle mass. Hand-grip strength and gait speed are simple tools to gauge muscle strength and performance, respectively. Sarcopenia, sarcopenic obesity, and myosteatosis portend poor outcomes. Sarcopenia contributes greatly to frailty, which is a syndrome of reduced physiological reserve and impaired response to stressors. Dietary interventions must ensure adequate calorie (35-40 kcal/kg/day) and protein (1.2-1.5 gm/kg/day) intake via multiple frequent meals and late-evening calorie-dense snack. Micronutrient supplementation is essential, keeping in mind the etiology of cirrhosis. Individualized, gradually up-titrated exercise prescription consisting of both aerobic and resistance training of 150 min/week is advisable after appropriate risk assessment. Early initiation of enteral nutrition within 12-24 h of LT is recommended. Data with respect to immune-nutrition, monomeric formulas, and hormone replacement remain conflicting at present. A multidisciplinary team comprising of hepatologists, transplant surgeons, intensivists, dieticians, and physiotherapists is vital to improve overall nutrition and outcomes in this vulnerable group.

The impact of obesity on postoperative complications and short-term survival after liver transplantation

BACKGROUND AND AIMS

Obesity is considered a risk factor for perioperative complications, but its effect on patients undergoing liver transplantation (LT) remains unclear. This study was conducted to analyze the impact of obesity on early morbidity and mortality risk following LT.

METHODS

A multicenter study of outcomes in patients submitted to LT between 2009 and 2019 was conducted. Recipients were stratified into obese (BMI ≥ 30 kg/m2) and nonobese patients (BMI < 30 kg/m2). Early postoperative complications were compared and 30-day and 1-year patient and graft survival were assessed by Kaplan-Meier method. Primary graft nonfunction (PGNF) was defined as the presence of total bilirubin > 10 mg/dl, INR > 1.6 or ALT > 2000 U/l within the first week after LT.

RESULTS

A total of 1608 patients were included after applying exclusion criteria, nonobese (1149, 71.46%) and obese patients (459, 28.54%). There were no significant differences in age, sex, Model for End-stage Liver Disease, Charlson comorbidity score, ethnicity, waiting list time and ischemia time. There were significantly higher rates of vascular (17.58% vs 23.53%, P = 0.021) and biliary complications (27.68% vs 35.73%, P = 0.006) and PGNF (11.40% vs 12.20%, P = 0.021) in obese patients. There was a significantly increased risk for long-term graft failure; however, there was no significant difference in patient survival after LT.

CONCLUSION

Obese patients have significantly increased morbidity in terms of vascular and biliary complications and PGNF after LT. They have a higher risk for worse 1-year graft survival in comparison to controls.

Osteosarcopenia in NAFLD/MAFLD: An Underappreciated Clinical Problem in Chronic Liver Disease

Chronic liver disease (CLD), including non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), affects a significant portion of the population worldwide. NAFLD is characterised by fat accumulation in the liver, while NASH is associated with inflammation and liver damage. Osteosarcopenia, which combines muscle and bone mass loss, is an emerging clinical problem in chronic liver disease that is often underappreciated. The reductions in muscle and bone mass share several common pathophysiological pathways; insulin resistance and chronic systemic inflammation are the most crucial predisposing factors and are related to the presence and gravity of NAFLD and to the worsening of the outcome of liver disease. This article explores the relationship between osteosarcopenia and NAFLD/MAFLD, focusing on the diagnosis, prevention and treatment of this condition in patients with CLD.

Main factors influencing long-term outcomes of liver transplantation in 2022

Liver transplant (LT) outcomes have markedly improved in the recent decades, even if long-term morbidity and mortality are still considerable. Most of late deaths are independent from graft function and different comorbidities, including complications of metabolic syndrome and de novo neoplasms, seem to play a key role in determining long-term outcomes in LT recipients. This review discusses the main factors associated with late mortality and suggests possible strategies to improve long-term management and follow-up after liver transplantation. In particular, the reduction of drug toxicity, the use of tools to identify high-risk patients, and setting up a multidisciplinary team also for long-term management of LT recipients may further improve survival after liver transplantation.

Liver transplantation for non-alcoholic fatty liver disease: indications and post-transplant management

Non-alcoholic fatty liver disease (NAFLD) is currently the fastest growing indication to liver transplantation (LT) in Western Countries, both for end stage liver disease and hepatocellular carcinoma. NAFLD/non-alcoholic steatohepatitis (NASH) is often expression of a systemic metabolic syndrome; therefore, NAFLD/NASH patients require a multidisciplinary approach for a proper pre-surgical evaluation, which is important to achieve a post-transplant outcome comparable to that of other indications to LT. NAFLD/NASH patients are also at higher risk of post-transplant cardiovascular events, diabetes, dyslipidemia, obesity, renal impairment and recurrent NASH. Lifestyle modifications, included diet and physical activity, are key to improve survival and quality of life after transplantation. A tailored immunosuppressive regimen may be proposed in selected patients. Development of new drugs for the treatment of recurrent NASH is awaited.

Sarcopenic obesity and therapeutic outcomes in gastrointestinal surgical oncology: A meta-analysis

Background

Sarcopenic obesity (SO) has been indicated as a scientific and clinical priority in oncology. This meta-analysis aimed to investigate the impacts of preoperative SO on therapeutic outcomes in gastrointestinal surgical oncology.

Methods

We searched the PubMed, EMBASE, and Cochrane Library databases through March 4th 2022 to identify cohort studies. Endpoints included postoperative complications and survival outcomes. Newcastle Ottawa Scale was used for quality assessment. Heterogeneity and publication bias were assessed. Subgroup analyses and sensitivity analyses were performed.

Results

Twenty-six studies (8,729 participants) with moderate to good quality were included. The pooled average age was 65.6 [95% confidence interval (CI) 63.7–67.6] years. The significant heterogeneity in SO definition and diagnosis among studies was observed. Patients with SO showed increased incidences of total complications (odds ratio 1.30, 95% CI: 1.03–1.64, P = 0.030) and major complications (Clavien-Dindo grade ≥ IIIa, odds ratio 2.15, 95% CI: 1.39–3.32, P = 0.001). SO was particularly associated with the incidence of cardiac complications, leak complications, and organ/space infection. SO was also predictive of poor overall survival (hazard ratio 1.73, 95% CI: 1.46–2.06, P &lt; 0.001) and disease-free survival (hazard ratio 1.41, 95% CI: 1.20–1.66, P &lt; 0.001). SO defined as sarcopenia in combination with obesity showed greater association with adverse outcomes than that defined as an increased ratio of fat mass to muscle mass. A low prevalence rate of SO (&lt; 10%) was associated with increased significance for adverse outcomes compared to the high prevalence rate of SO (&gt; 20%).

Conclusion

The SO was associated with increased complications and poor survival in gastrointestinal surgical oncology. Interventions aiming at SO have potentials to promote surgery benefits for patients with gastrointestinal cancers. The heterogeneity in SO definition and diagnosis among studies should be considered when interpreting these findings.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=255286], identifier [CRD42021255286].

Association of obesity with mortality and clinical outcomes in children and adolescents with transplantation: A systematic review and meta-analysis

Obesity might be associated with mortality and clinical outcomes following transplantation; however, the direction of this relationship has not been well-recognized in youth. The aim of this systematic review and meta-analysis was to investigate the association of obesity with post-transplant mortality and clinical outcomes in children and adolescents. Following a systematic search of observational studies published by December 2018 in PubMed, Scopus, Embase, and Cochrane library, 15 articles with total sample size of 50,498 patients were included in the meta-analysis. The main outcome was mortality and secondary outcomes included acute graft versus host disease (GVHD), acute rejection, and overall graft loss. The pooled data analyses showed significantly higher odds of long term mortality (OR 1.30, 95% CI 1.15-1.48, P < 0.001, I² = 50.3%), short term mortality (OR 1.79, 95% CI 1.19-2.70, P = 0.005, I² = 59.6%), and acute GVHD (OR 2.13, 95% CI 1.5-3.02, P < 0.001, I² = 1.7%) in children with obesity. There were no significant differences between patients with and without obesity in terms of acute rejection (OR 1.07, 95% CI 0.98-1.16, P = 0.132, I² = 7.5%) or overall graft loss (OR 1.04, 95% CI 0.84-1.28, P = 0.740, I² = 51.6%). This systematic review and meta-analysis has stated higher post-transplant risk of short and long term mortality and higher risk of acute GVHD in children with obesity compared to those without obesity. Future clinical trials are required to investigate the effect of pre-transplant weight management on post-transplant outcomes to provide insights into the clinical application of these findings. This may in turn lead to establish guidelines for the management of childhood obesity in transplantations.

Metabolic Complications in Liver Transplantation Recipients: How We Can Optimize Long-Term Survival

Liver transplantation (LT) recipients have experienced a significant improvement in short-term survival during the past 3 decades attributed to advancements in surgical techniques, perioperative management, and effective immunosuppressive regimens. However, long-term survival is affected by a high incidence of metabolic disorders and their consequences, including cardiovascular disease (CVD) and malignancies. Pretransplant metabolic impairments especially in those with nonalcoholic steatohepatitis cirrhosis are aggravated by the addition of posttransplant weight gain, physical inactivity, and reversal from catabolic to anabolic state. Moreover, although immunosuppressants are vital to avoid graft rejection, long-term exposure to these medications is implicated in metabolic impairments after LT. In this review, we summarize the molecular pathogenesis of different metabolic disorders after LT, including diabetes mellitus, dyslipidemia, and nonalcoholic fatty liver disease. Furthermore, CVD, malignancies, and graft rejections were provided as significant complications of post-LT metabolic conditions threatening both the patient and graft survival. Ultimately, emerging preventive and treatment strategies for posttransplant diabetes mellitus are summarized. This review highlights the significant need for more clinical trials of antihyperglycemic agents in LT recipients. Also, translational studies will help us to better understand the molecular and genetic factors underlying these metabolic complications and could lead to more personalized management in this high-risk population.

Frailty in Nonalcoholic Fatty Liver Cirrhosis: A Comparison with Alcoholic Cirrhosis, Risk Patterns, and Impact on Prognosis

BACKGROUND

Physical frailty increases susceptibility to stressors and predicts adverse outcomes of cirrhosis. Data on disease course in different etiologies are scarce, so we aimed to compare the prevalence and risk factors of frailty and its impact on prognosis in nonalcoholic fatty liver (NAFLD) and alcoholic (ALD) cirrhosis. Patients and Methods. Cirrhosis registry RH7 operates since 2014 and includes hospitalized patients with decompensated cirrhosis, pre-LT evaluation, or curable hepatocellular carcinoma (HCC). From the RH7, we identified 280 ALD and 105 NAFLD patients with at least 6 months of follow-up.

RESULTS

Patients with NAFLD compared with ALD were older and had a higher proportion of females, higher body mass index (BMI) and mid-arm circumference (MAC), lower MELD score, CRP, and lower proportion of refractory ascites. The liver frailty index did not differ, and the prevalence of HCC was higher (17.1 vs. 6.8%, p=0.002). Age, sex, serum albumin, and C-reactive protein (CRP) were independent predictors of frailty. In NAFLD, frailty was also associated with BMI and MAC and in ALD, with the MELD score. The Cox model adjusted for age, sex, MELD, CRP, HCC, and LFI showed that NAFLD patients had higher all-cause mortality (HR = 1.88 95% CI 1.32-2.67, p < 0.001) and were more sensitive to the increase in LFI (HR = 1.51, 95% CI 1.05-2.2).

CONCLUSION

Patients with NAFLD cirrhosis had a comparable prevalence of frailty compared to ALD. Although prognostic indices showed less advanced disease, NAFLD patients were more sensitive to frailty, which reflected their higher overall disease burden and led to higher all-cause mortality.

Abdominal Organ Transplantation: Noteworthy Literature in 2020

In 2020, we identified and screened over 490 peer-reviewed publications on pancreatic transplantation, over 500 on intestinal transplantation, and over 5000 on kidney transplantation. The liver transplantation section specially focused on clinical trials and systematic reviews published in 2020 and featured selected articles. This review highlights noteworthy literature pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. We explore a wide range of topics, including COVID-19 and organ transplantation, risk factors and outcomes, pain management, artificial intelligence, robotic donor surgery, and machine perfusion.