Association between sarcopenia and the risk of serious infection among adults undergoing liver transplantation

Sarcopenia in high acuity liver transplantation: Does it predict outcomes?

BACKGROUND

Sarcopenia has gained momentum as a potential risk-stratification tool in liver transplantation (LT). While LT recipients recently have more advanced end-stage liver disease, the impact of sarcopenia in high acuity recipients with a high model for end-stage liver disease (MELD) score remains unclear.

METHODS

We retrospectively assessed sarcopenia by calculating skeletal muscle index (SMI) from cross-sectional area at third lumbar vertebra (cm² ) and height (m² ) in 296 patients with a CT ≤ 30 days prior to LT. Sex-specific SMI cut-offs were developed, and its impact was assessed in patients with MELD ≥ 35.

RESULTS

In patients with MELD ≥ 35 (n = 217), men with a SMI < 30 cm² /m² had significantly higher rates of bacteremia (P = .021) and a longer hospital stay (P < .001). Women with a SMI < 34 cm² /m² had a longer hospital stay (P = .032). There were no relationships between SMI and survival in men and women with MELD ≥ 35.

CONCLUSIONS

This series examined sarcopenia with a focus on high MELD patients. Although decreased SMI contributed to higher post-LT hospital stay, it did not impact patient survival, suggesting that while SMI alone may not aid in patient selection for LT, it certainly may guide perioperative care-planning in this challenging patient population.

Sarcopenia adversely impacts postoperative complications in living-donor liver transplantation recipients

Despite technological and immunological innovations, living-donor liver transplant (LDLT) recipients still face substantial risk of postoperative complications. Sarcopenia is being recognized more and more as a biomarker that correlates with poor outcomes in surgical patients. The purpose of this study was to evaluate the relationship between sarcopenia and significant surgical complications in LDLT recipients. This retrospective review included patients who had received LDLT at our institute from 2005 to 2017. Sarcopenia was assessed using the psoas muscle index (PMI) in cross-sectional images. ROC curve analysis was used to determine the ability of PMI to predict postoperative complications. Correlations between major postoperative complications and sarcopenia were evaluated using regression analysis. A total of 271 LDLT recipients were included. No significant differences were found between PMI and major postoperative complications in male patients. Female recipients with major postoperative complications had significantly lower mean PMI values (P = 0.028), and the PMI cut-off value was 2.63 cm²/m². Postoperative massive pleural effusion requiring pigtail drainage occurred more frequently in the sarcopenia group than in the non-sarcopenia group (P = 0.003). 1-, 3-, 5- and 10-year overall survival rates in female were significantly poorer in the sarcopenia group (n = 14) compared with the non-sarcopenia group (n = 108), at 92.9% versus 97.2%, 85.7% versus 95.4%, 85.7% versus 92.5% and 70.1 versus 82.0%, respectively (P = 0.041) and 94.6%, 89.9%, 85.9% and 78.5% in male patients. Sarcopenia is associated with a significantly higher risk of major postoperative complications in females. PMI and sarcopenia together are predictive of major postoperative complications and survival rates in female LDLT recipients.

Phase Angle From Bioelectrical Impedance for the Assessment of Sarcopenia in Cirrhosis With or Without Ascites

BACKGROUND AND AIMS

Skeletal muscle index (SMI) from computed tomography (CT) reliably assesses sarcopenia, however, it is expensive and involves serial radiation exposure. Phase angle (PhA) from bioimpedance analysis (BIA) is a noninvasive, low cost, bedside nutritional tool used to monitor changes to nutritional interventions. We aimed to compare the performance of PhA with SMI to assess sarcopenia in cirrhosis.

METHODS

Ambispective cohort study. Consecutive patients with cirrhosis and available images from abdominal CT scan were included. Monofrequency BIA was performed within 2 weeks CT. Spearman's correlation, ROC curve, and survival analysis with Kaplan-Meier, Cox and competing-risk regression were performed.

RESULTS

136 patients were included with a mean age of 54.5 years (60% female). Most had decompensated disease (66%) with ascites in 47%, and a mean MELD of 14 ± 6. We found positive correlations between SMI and PhA (r = 0.58 , P < .001), irrespective of the presence of ascites. The AUROC of PhA-sarcopenia in all patients was 0.702; (0.748 in males,0.677 in females). The best cutoffs of PhA for diagnosing sarcopenia were ≤5.6° in males and ≤5.4° in females. SMI and PhA were significantly associated with survival in Kaplan-Meier curves. In multivariable analyses, SMI was outperformed by age and MELD, whereas PhA remained independently associated with mortality. Considering transplantation as a competing risk, regression analysis showed both SMI and PhA to be independent predictors of mortality (sHR:0.95 [0.90-0.99] and sHR:0.61 [0.42-0.88]).

CONCLUSION

PhA moderately correlates with SMI for the identification of sarcopenia in patients with cirrhosis. However, its prognostic accuracy is comparable to that of SMI, and it is not influenced by ascites.

Physical frailty in liver transplantation

In patients with cirrhosis, frailty represents a status of global physical dysfunction associated with a multiplicity of factors, including muscle wasting, undernutrition and malnutrition, and functional impairment. This condition is particularly prevalent among those with advanced cirrhosis, such as liver transplant (LT) candidates. Studies in this vulnerable population have demonstrated that its presence is independently predictive of adverse outcomes both pre- and post-transplantation, and thus that its incorporation into clinical practice could result in improved clinical decision-making, particularly regarding the identification of candidates for physical and nutritional interventions. There are, however, some limitations to its immediate incorporation into organ allocation prioritization models, including the wide heterogeneity of instruments used for measuring frailty, and particularly the lack of a single one suitable in all LT clinical scenarios (inpatient vs outpatient; pre- vs post-transplant). Finally, the data on the potential effects of frailty improvement on the diverse range of outcome measures are still preliminary.

Frailty in Pancreas Transplantation

There are a variety of definitions and criteria used in clinical practice to define frailty. In the absence of a gold-standard definition, frailty has been operationally defined as meeting 3 out of 5 phenotypic criteria indicating compromised function: low grip strength, low energy, slowed walking speed, low physical activity, and unintentional weight loss. Frailty is a common problem in solid organ transplant candidates who are in the process of being listed for a transplant, as well as after transplantation. Patients with diabetes or chronic kidney disease (CKD) are known to be at increased risk of being frail. As pancreas transplantation is exclusively performed among patients with diabetes and the majority of them also have CKD, pancreas transplant candidates and recipients are at high risk of being frail. Sarcopenia, fatigue, low walking speed, low physical activity, and unintentional weight loss, which are some of the phenotypes of frailty, are very prevalent in this population. In various solid organs, frail patients are less likely to be listed or transplanted and have high waitlist mortality. Even after a transplant, they have increased risk of prolonged hospitalization, readmission, and delayed graft function. Given the negative impact of frailty on solid organ transplants, we believe that frailty would have a similar or even worse impact on pancreas transplantation. Due to the paucity of data specifically among pancreas transplant recipients, here we include frailty data from patients with CKD, diabetes, and various solid organ transplant recipients.

Impact of sarcopenia in infants with liver transplantation for biliary atresia

While sarcopenia is an important predictor of LT outcomes in adults, few studies have examined the association of sarcopenia with LT outcomes in pediatric patients. We investigated the clinical influence of sarcopenia on the post-transplant outcomes in infants with BA. To define sarcopenia in infants, the cross-sectional area of the tPMA in 93 healthy control infants was measured by computed tomography. Sarcopenia was defined as a tPMA lower than two standard deviations below the mean of healthy control infants. Eighty-nine infants with BA with a median age at LT of 7.6 months old were enrolled. The clinical characteristics and outcomes of LT were verified in the sarcopenia group (n = 21) and non-sarcopenia group (n = 68). The sarcopenia group had a significantly longer operation time and greater blood loss during LT than the non-sarcopenia group (P = .03 and 0.02). The incidence of portal vein stenosis and post-operative bloodstream infection was also significantly higher in the sarcopenia group than in the non-sarcopenia group (23.8% vs 4.4%, P = .02 and 28.6% vs 10.3%, P = .04, respectively). The total length of hospital stay did not differ significantly. The 1-year patient and graft survival rates tended to be lower in the sarcopenia group than in the non-sarcopenia group (90.5% vs 98.5%, P = .07 and 85.7% vs 97.1%, P = .05, respectively). Sarcopenia in infants with BA may be associated with the patient survival and serve as an effective marker for post-operative outcomes of LT.

Sarcopenia-The Impact on Physical Capacity of Liver Transplant Patients

Optimizing patients' condition before liver transplantation (LT) could potentially improve survival of LT patients. We focused on sarcopenia, as a common factor in liver transplant candidates that can impact their cardiopulmonary performance at the point of listing, morbidity, and mortality after LT. We performed a single-center cohort study on 98 consecutive patients with liver cirrhosis who were transplanted between March 2015 and December 2017. The third lumbar vertebra skeletal muscle index (L3SMI) was calculated using CT imaging to distinguish sarcopenia at listing for LT. Data regarding liver function, body mass index (BMI), cardiac biomarkers, the peak oxygen uptake (VO2) and LT outcome were collected and correlated to L3SMI. For data analysis the Dell Statistica (Version 13. Dell Inc., Rondrock, TX, USA) was used. In total, 98 cirrhotic patients were included. Fifty-five (56.1%) patients, mostly males, had sarcopenia according to L3SMI, with the lowest L3SMI in males with alcohol-related liver disease. Lower L3SMI correlated with lower BMI, lower VO2 peak, and higher NTproBNP (all p < 0.001) and revealed an essential correlation with prolonged ICU stay (r = -0.21, p < 0.05). 33 patients were unable to perform cardio-pulmonary exercise test, mostly sarcopenic (67%), with more advanced liver insufficiency (assessed with CPC and MELD scores) and longer stay at ICU after LT (all p < 0.001). Sarcopenia was common among LT recipients. It was associated with inferior result in cardio-pulmonary performance before LT and prolonged ICU stay after grafting.

Impact of sarcopenia on clinical outcomes of patients undergoing simultaneous liver and kidney transplantation: a cohort study

BACKGROUND

The impact of sarcopenia in patients undergoing simultaneous liver and kidney transplantation (SLKT) has not been fully delineated. The aim of this single-centre-cohort-study was to evaluate the impact of sarcopenia on the clinical outcomes.

METHODS

Between 2003 and 2018, 79 patients underwent SLKT. Sarcopenia was assessed via the total psoas muscle area (TPA) at the level of the 3rd. lumbar vertebra. Sarcopenia threshold was TPA < 1460 mm² (women) and <1560 mm² (men). We identified post-operative biliary, vascular and digestive complications. Survival analysis was performed by the Kaplan Meier method (log-rank test).

RESULTS

We included 43/79 SLKT recipients (56%male, median age of 58 [53-63] years). The prevalence of cirrhosis was 74% (n = 32) with median MELD-score of 21 (20-22) and that of polycystic-liver-disease was 26% (n = 11). End-stage-renal-disease of unknown origin was 36.2% (n = 12). Dialysis before transplantation was performed in 54,8% (n = 23) of patients. The median TPA was 1138 (926-1510) mm², and sarcopenia was detected in 72% of patients (n = 31). No difference in patient or death-censored graft-survival between sarcopenic and non-sarcopenic groups at 1 year was reported. Also, no differences at 6-months' post-transplant-complication-free and infection-free-survival rates were found.

CONCLUSION

In this cohort of patients, no differences were observed in patients, grafts, complications or infection-free survival between sarcopenic or no sarcopenic SLKT patients. Future multi-centre studies are needed to validate and extend the generalisability of these findings.

Sarco-Model: A score to predict the dropout risk in the perspective of organ allocation in patients awaiting liver transplantation

BACKGROUND & AIMS

Sarcopenia in liver transplantation (LT) cirrhotic candidates has been connected with higher dropouts and graft losses after transplant. The study aims to create an 'urgency' model combining sarcopenia and Model for End-stage Liver Disease Sodium (MELDNa) to predict the risk of dropout and identify an appropriate threshold of post-LT futility.

METHODS

A total of 1087 adult cirrhotic patients were listed for a first LT during January 2012 to December 2018. The study population was split into a training (n = 855) and a validation set (n = 232).

RESULTS

Using a competing-risk analysis of cause-specific hazards, we created the Sarco-Model2 . According to the model, one extra point of MELDNa was added for each 0.5 cm2 /m2 reduction of total psoas area (TPA) < 6.0 cm2 /m2 . At external validation, the Sarco-Model2 showed the best diagnostic ability for predicting the risk of 3-month dropout in patients with MELDNa < 20 (area under the curve [AUC] = 0.93; P = .003). Using the net reclassification improvement, 14.3% of dropped-out patients were correctly reclassified using the Sarco-Model2 . As for the futility threshold, transplanted patients with TPA < 6.0 cm2 /m2 and MELDNa 35-40 (n = 16/833, 1.9%) had the worse results (6-month graft loss = 25.5%).

CONCLUSIONS

In sarcopenic patients with MELDNa < 20, the 'urgency' Sarco-Model2 should be used to prioritize the list, while MELDNa value should be preferred in patients with MELDNa ≥ 20. The Sarco-Model2 played a role in more than 30% of the cases in the investigated allocation scenario. In sarcopenic patients with a MELDNa value of 35-40, 'futile' transplantation should be considered.

Sarcopenia and frailty in decompensated cirrhosis

In patients with decompensated cirrhosis, sarcopenia and frailty are prevalent. Although several definitions exist for these terms, in the field of hepatology, sarcopenia has commonly been defined as loss of muscle mass, and frailty has been broadly defined as the phenotypic manifestation of the loss of muscle function. Prompt recognition and accurate assessment of these conditions are critical as they are both strongly associated with morbidity, mortality, poor quality of life and worse post-liver transplant outcomes in patients with cirrhosis. In this review, we describe the complex pathophysiology that underlies the clinical phenotypes of sarcopenia and frailty, their association with decompensation, and provide an overview of tools to assess these conditions in patients with cirrhosis. When available, we highlight data focusing on patients with acutely decompensated cirrhosis, such as inpatients, as this is an area of unmet clinical need. Finally, we discuss management strategies to reverse and/or prevent the development of sarcopenia and frailty, which include adequate nutritional intake of calories and protein, as well as regular exercise of at least moderate intensity, with a mix of aerobic and resistance training. Key knowledge gaps in our understanding of sarcopenia and frailty in decompensated cirrhosis remain, including best methods to measure muscle mass and function in the inpatient setting, racial/ethnic variation in the development and presentation of sarcopenia and frailty, and optimal clinical metrics to assess response to therapeutic interventions that translate into a reduction in adverse outcomes associated with these conditions.

[Sarcopenia and Cachexia-associated Risk in Surgery]

Cachexia is defined as a multifactorial syndrome characterised by involuntary progressive weight loss due to a decrease in skeletal muscle mass, with or without a reduction in adipose tissue. The breakdown of muscle tissue is known as sarcopenia. This is clinically defined as loss of muscle mass and/or muscle strength, with loss of muscle strength being more important than muscle mass. Cachexia is responsible for the death of at least 20% of all cancer patients. The incidence in these patients varies, depending on the type of disease, between 80% for patients with gastric and pancreatic cancer, 50% for patients with lung, colon and prostate cancer, and about 40% for patients with breast cancer or leukemia. It is often difficult to distinguish between tumour-associated cachexia and cachexia caused by side effects and complications of oncological therapy. The main clinical feature of cachexia is involuntary weight loss, but this does not always manifest itself clinically, making it much more difficult to identify patients at risk. Not only the long-term outcome of the patient is influenced by cachexia and sarcopenia. Immediate postoperative complication rates (morbidity) are also increased and have profound effects on the burden of disease and the suffering of patients after surgical treatment. Cachexia, sarcopenia and myosteatosis are therefore highly relevant parameters for everyday clinical practice, which have a significant influence on the postoperative outcome of the patient. Several tools have been developed to aid the identification of patients with nutritional risk, i.e. involuntary weight loss, reduced muscle strength and physical condition. Such measures should be a part of our daily clinical routine to ensure the identification of patients with the highest postoperative risk. Novel preconditioning treatment may be beneficial to certain patient groups to reduce postoperative morbidity.

Higher Mortality in Pediatric Liver Transplant Candidates With Sarcopenia

Little is known about the impact of sarcopenia (reduced muscle mass and function) in pediatric chronic liver disease. We compared psoas muscle surface area (PMSA), measured at the 4th lumbar vertebrae, in children listed for liver transplantation (LT) to that of healthy controls and studied the impact of sarcopenia on transplant-associated outcomes. The effect of PMSA (raw value and z score) on survival was studied using multivariable proportional hazards, whereas the impact of PMSA on other transplant-associated outcomes was assessed by multivariable linear or logistic regression. The correlation of PMSA with anthropometric values and markers of disease severity was studied using Spearman's rank-order correlation. Mean PMSA was significantly lower in LT candidates (n = 57, 699.4 ± 591.9 mm² [mean ± SD]) than controls (n = 53, 1052.9 ± 960.7 mm² ; P = 0.02). For LT candidates, there was an increased risk of death (either while on the waiting list or following transplantation) with lower PMSA (hazard ratio [HR], 1.6 per 100 mm² [P = 0.03]; 95% confidence interval [CI], 1.1-2.8), amounting to a 4.9 times higher risk of death for every 1 unit decrease in PMSA z score (HR, 4.9 [P = 0.05], 95% CI, 1.2-34.5), adjusting for age and sex. PMSA did not correlate with posttransplant length of intubation, hospital length of stay, or perioperative complications. PMSA also did not correlate with calculated (r = 0.10, P = 0.60) or appealed Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease scores (r = 0.10, P = 0.69). Pediatric LT candidates have a significant reduction in muscle compared with controls. LT candidates with lower PMSA experience significant increases in mortality. As such, sarcopenia may provide a novel indicator of disease severity in children with chronic liver disease.

Non-Selective Beta-Blockers Decrease Infection, Acute Kidney Injury Episodes, and Ameliorate Sarcopenic Changes in Patients with Cirrhosis: A Propensity-Score Matching Tertiary-Center Cohort Study

Background: Cirrhotic complications resulting from portal hypertension can be considerably reduced by non-selective beta-blockers (NSBBs); however, scarce studies have investigated therapeutic agents for other complications. We aimed to investigate the effects of NSBBs on common cirrhotic complications of infection, acute kidney injury (AKI), chronic renal function declination, and sarcopenic changes. Methods: Medical records of hospitalization for cirrhosis with at least a 4-year follow-up were analyzed and selected using propensity-score matching (PSM). Generalized estimating equation (GEE) was applied to assess the association of NSBBs with infection requiring hospitalization and AKI. Chronic renal function declination was evaluated by slope of regression lines derived from reciprocal of the serum creatinine level. The covariates of CT-measured skeletal muscle index (SMI) alterations were analyzed by generalized linear mixed model. Results: Among the 4946 reviewed individuals, 166 (83 NSBB group, 83 non-NSBB group) were eligible. Using GEE, Charlson comorbidity index, Child-Pugh score and non-NSBB were risk factors for infection; non-NSBB group revealed a robust trend toward AKI, showed no significant difference with chronic renal function declination of NSBB group, and was negatively associated with SMI alteration. Conclusion: Chronic NSBB use lowered the episodes of infection requiring hospitalization and AKIs, whereas non-NSBB was associated with sarcopenic changes.

Sarcopenia in Children With End-Stage Liver Disease on the Transplant Waiting List

Sarcopenia predicts morbidity and mortality in adults with end-stage liver disease (ESLD) and is determined by total psoas muscle area (tPMA) measurement from computed tomography (CT) imaging. Recently developed pediatric age- and sex-specific tPMA growth curves provide the opportunity to ascertain prevalence and impact of sarcopenia in children awaiting liver transplantation (LT). This retrospective single-center study evaluated sarcopenia in children between 1 and 16 years with ESLD and a clinically indicated abdominal CT less than 3 months before first isolated LT. Sarcopenia was defined as tPMA z score less than -2 measured at the intervertebral L4-5 level. Patient demographic, biochemical, and outcome data were recorded. tPMA was compared with other measures of nutritional status using univariate and multivariate logistic analyses. Outcome measures included 1-year morbidity events and mortality after LT. CT images from 25 (64% female) children with median age of 5.50 (interquartile range [IQR], 3.75-11.33) years were reviewed. Ten children (40%) had a tPMA z score less than -2. Sarcopenia was associated with lower z scores for weight (odds ratio [OR], 0.38; P = 0.02), height (OR, 0.32; P = 0.03), and nutritional support before LT (OR, 12.93; P = 0.01). Sarcopenic children had a longer duration of pediatric intensive care unit (PICU) stay (3.50 [IQR, 3.00-6.00] versus 2.00 [IQR, 2.00-3.50] days; P = 0.03). Sarcopenia was prevalent in 40% of children with ESLD awaiting LT, and lower tPMA z score was associated with deficient anthropometrics and need for nutritional support before LT. Post-LT PICU duration was increased in children with sarcopenia, reflecting adverse outcomes associated with muscle loss. Further studies are needed to elucidate the underlying mechanisms of sarcopenia in children with ESLD.

Definition of Sarcopenia in Chronic Liver Disease

Sarcopenia, which is characterized by decline in muscle mass, muscle strength, and physical performance, is common in patients with chronic liver disease (CLD) and is associated with poor clinical outcomes. Several consensus definitions for community-dwelling elderly people have been proposed, and these recommend the use of various tools and tests to assess muscle properties and performance. These measurement tools have also been applied in patients with CLD and have been useful for predicting prognosis. However, sarcopenia and its diagnostic criteria specific to patients with CLD have not yet been clearly defined. In addition, fluid retention and body composition should be considered when sarcopenia is assessed in patients with CLD. This review aims to introduce definitions of sarcopenia and diagnostic tools used in patients with CLD.

The role of recipient myosteatosis in graft and patient survival after deceased donor liver transplantation

BACKGROUND

Myosteatosis is associated with perioperative outcomes in orthotopic liver transplantation (OLT). Here, we investigated the effects of body composition and myosteatosis on long-term graft and patient survival following OLT.

METHODS

Clinical data from 225 consecutive OLT recipients from a prospective database were retrospectively analysed (May 2010 to December 2017). Computed tomography-based lumbar skeletal muscle index (SMI) (muscle mass) and mean skeletal muscle radiation attenuation (SM-RA) (myosteatosis) were calculated using a segmentation tool (3D Slicer). Patients with low skeletal muscle mass (low SMI) and myosteatosis (low SM-RA) were identified using predefined and validated cut-off values.

RESULTS

The mean donor and recipient age was 55 ± 16 and 54 ± 12 years, respectively. Some 67% of the recipients were male. The probability of graft and patient survival was significantly lower in patients with myosteatosis compared with patients with higher SM-RA values (P = 0.011 and P = 0.001, respectively). Low skeletal muscle mass alone was not associated with graft and patient survival (P = 0.273 and P = 0.278, respectively). Dividing the cohort into quartiles, based on the values of SMI and SM-RA, resulted in significant differences in patient but not in graft survival (P = 0.011). Even though multivariable analysis identified low SM-RA as an important prognostic marker (hazard ratio: 2.260, 95% confidence interval: 1.177-4.340, P = 0.014), myosteatosis lost its significance when early mortality (90 days) was excluded from the final multivariable model. Patients with myosteatosis showed significantly higher all-cause mortality and in particular higher rates of deaths due to respiratory and septic complication (P = 0.002, P = 0.022, and P = 0.049, respectively).

CONCLUSIONS

Preoperative myosteatosis may be an important prognostic marker in patients undergoing deceased donor liver transplantation. The prognostic value of myosteatosis seems to be particularly important in the early post-operative phase. Validation in prospective clinical trials is warranted.

Recommendations and guidance on nutritional supplementation in the liver transplant setting

Malnutrition is a frequent complication in patients with cirrhosis and liver transplant (LT) candidates. It is highly related to sarcopenia, and their implications in morbidity and mortality go beyond the waiting list period throughout the post-LT. However, there are no specific interventions defined by guidelines, regarding the kind or the timing of the nutritional intervention to improve LT outcomes. Results from studies developed in the LT setting and evaluating their impact on the LT candidates or recipients are discussed in this review, and new research lines are presented.

An Overview of the Molecular Mechanisms Contributing to Musculoskeletal Disorders in Chronic Liver Disease: Osteoporosis, Sarcopenia, and Osteoporotic Sarcopenia

The prevalence of osteoporosis and sarcopenia is significantly higher in patients with liver disease than in those without liver disease and osteoporosis and sarcopenia negatively influence morbidity and mortality in liver disease, yet these musculoskeletal disorders are frequently overlooked in clinical practice for patients with chronic liver disease. The objective of this review is to provide a comprehensive understanding of the molecular mechanisms of musculoskeletal disorders accompanying the pathogenesis of liver disease. The increased bone resorption through the receptor activator of nuclear factor kappa (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) system and upregulation of inflammatory cytokines and decreased bone formation through increased bilirubin and sclerostin and lower insulin-like growth factor-1 are important mechanisms for osteoporosis in patients with liver disease. Sarcopenia is associated with insulin resistance and obesity in non-alcoholic fatty liver disease, whereas hyperammonemia, low amount of branched chain amino acids, and hypogonadism contributes to sarcopenia in liver cirrhosis. The bidirectional crosstalk between muscle and bone through myostatin, irisin, β-aminoisobutyric acid (BAIBA), osteocalcin, as well as the activation of the RANK and the Wnt/β-catenin pathways are associated with osteosarcopenia. The increased understandings for these musculoskeletal disorders would be contributes to the development of effective therapies targeting the pathophysiological mechanism involved.

The impact of L-branched-chain amino acids and L-leucine on malnutrition, sarcopenia, and other outcomes in patients with chronic liver disease

INTRODUCTION

Metabolic and hormonal disorders resulting from chronic liver diseases culminate in increased proteolysis and decreased protein synthesis, which contributes to the development and progression of malnutrition and, consequently, sarcopenia. Nutritional management of sarcopenia in liver cirrhosis is a continuously evolving field and data on essential amino acid supplementation in chronic liver diseases is scarce.

AREAS COVERED

This review encompasses the current literature on oral amino acids supplementation in patients with chronic liver disease or patients with liver cirrhosis to try to elucidate the possible effects of L-branched-chain amino acids and isolated L-leucine as a therapeutic approach to malnutrition and sarcopenia.

EXPERT COMMENTARY

To ensure an optimal nutritional status and to reduce sarcopenia, it is necessary to assess nutritional status in all patients with liver cirrhosis and to apply nutritional interventions accordingly. The supply of calories, proteins, and essential amino acids is necessary for the maintenance of muscle mass and function. Although supplementation of L-branched-chain amino acids plays an important role in liver disease, L-leucine has been described as the main amino acid involved in protein turnover, reducing proteolysis, and stimulating protein synthesis.

Frailty and Sarcopenia in Patients Pre- and Post-Liver Transplant

Greater than half of patients with decompensated liver disease suffer from frailty and/or sarcopenia, which can lead to increased pre- and post-liver transplant morbidity and mortality. Although frailty and sarcopenia can impact patients with end-stage liver disease in similar ways, they are unique clinical entities with differing underlying etiologies. Early assessment and identification of frailty and sarcopenia in patients is critical to guide clinical decision-making regarding transplantation and to implement nutritional and exercise-based treatment regiments. Nonetheless, accurate diagnosis and, in particular, predicting patients that will develop frailty and/or sarcopenia remains challenging, and the success of clinical interventions is limited.

The effect of malnutrition on the infectious outcomes of hospitalized patients with cirrhosis: analysis of the 2011-2017 hospital data

BACKGROUND

In patients with cirrhosis, there is a clinical concern that the development of protein-calorie malnutrition will affect the immune system and predispose these patients to increased infectious outcomes.

AIMS

In this study, we evaluate the effects of malnutrition on the infectious outcomes of patients admitted with cirrhosis.

MATERIALS AND METHODS

This study used the 2011-2017 National Inpatient Sample to identify patients with cirrhosis. These patients were stratified using malnutrition (protein-calorie malnutrition, cachexia, and sarcopenia) and matched using age, gender, and race with 1:1 nearest neighbor matching method. The endpoints included mortality and infectious outcomes.

RESULTS

After matching, there were 96 842 malnutrition-present cohort and equal number of controls. In univariate analysis, the malnutrition cohort had higher hospital mortality [10.40 vs. 5.04% P < 0.01, odds ratio (OR) 2.18, 95% confidence interval (CI) 2.11-2.26]. In multivariate models, malnutrition was associated with increased mortality [P < 0.01, adjusted odds ratio (aOR) 1.32, 95% CI 1.27-1.37] and infectious outcomes, including sepsis (P < 0.01, aOR 1.94, 95% CI 1.89-2.00), pneumonia (P < 0.01, aOR 1.68, 95% CI 1.63-1.73), UTI (P < 0.01, aOR 1.39, 95% CI 1.35-1.43), cellulitis (P < 0.01, aOR 1.09, 95% CI 1.05-1.13), cholangitis (P < 0.01, aOR 1.39, 95% CI 1.26-1.55), and clostridium difficile (P < 0.01, aOR 2.11, 95% CI 1.92-2.31).

CONCLUSION

The results of this study indicate that malnutrition is an independent risk factor of hospital mortality and local/systemic infections in patients admitted with cirrhosis.

Radiologic Definition of Sarcopenia in Chronic Liver Disease

Sarcopenia is prevalent in patients with chronic liver disease, and affected patients tend to have worse clinical outcomes and higher mortality. However, relevant analyses are limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing it. We reviewed several radiologic methods for sarcopenia in patients with chronic liver disease. Dual energy X-ray absorptiometry (DXA) can measure muscle mass, but it is difficult to evaluate muscle quality using this technique. Computed tomography, known as the gold standard for diagnosing sarcopenia, enables the objective measurement of muscle quantity and quality. The third lumbar skeletal muscle index (L3 SMI) more accurately predicted the mortality of subjects than the psoas muscle index (PMI). Few studies have evaluated the sarcopenia of chronic liver disease using ultrasonography and magnetic resonance imaging, and more studies are needed. Unification of the measurement method and cut-off value would facilitate a more systematic and universal prognosis evaluation in patients with chronic liver disease.

Radiologic Definition of Sarcopenia in Chronic Liver Disease

Sarcopenia is prevalent in patients with chronic liver disease, and affected patients tend to have worse clinical outcomes and higher mortality. However, relevant analyses are limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing it. We reviewed several radiologic methods for sarcopenia in patients with chronic liver disease. Dual energy X-ray absorptiometry (DXA) can measure muscle mass, but it is difficult to evaluate muscle quality using this technique. Computed tomography, known as the gold standard for diagnosing sarcopenia, enables the objective measurement of muscle quantity and quality. The third lumbar skeletal muscle index (L3 SMI) more accurately predicted the mortality of subjects than the psoas muscle index (PMI). Few studies have evaluated the sarcopenia of chronic liver disease using ultrasonography and magnetic resonance imaging, and more studies are needed. Unification of the measurement method and cut-off value would facilitate a more systematic and universal prognosis evaluation in patients with chronic liver disease.

Senolytic Drugs: Reducing Senescent Cell Viability to Extend Health Span

Senescence is the consequence of a signaling mechanism activated in stressed cells to prevent proliferation of cells with damage. Senescent cells (Sncs) often develop a senescence-associated secretory phenotype to prompt immune clearance, which drives chronic sterile inflammation and plays a causal role in aging and age-related diseases. Sncs accumulate with age and at anatomical sites of disease. Thus, they are regarded as a logical therapeutic target. Senotherapeutics are a new class of drugs that selectively kill Sncs (senolytics) or suppress their disease-causing phenotypes (senomorphics/senostatics). Since 2015, several senolytics went from identification to clinical trial. Preclinical data indicate that senolytics alleviate disease in numerous organs, improve physical function and resilience, and suppress all causes of mortality, even if administered to the aged. Here, we review the evidence that Sncs drive aging and disease, the approaches to identify and optimize senotherapeutics, and the current status of preclinical and clinical testing of senolytics.

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

Background: The rising prevalence of cirrhotic cases related to non-alcoholic steatohepatitis has led to an increased number of cirrhotic patients with coexistence of obesity and muscle mass loss, known as sarcopenic obesity (SO). In patients undergoing liver transplantation (LT), the presence of SO may worsen prognosis, and increase morbidity and mortality.

Objective: We aimed to evaluate the effect of the presence of pre-transplant SO on the outcomes of LT.

Methods: A comprehensive search was performed in seven medical databases for studies comparing morbidity and mortality of patients with and without SO after LT. The primary outcome was overall mortality in the short- (1 year), intermediate- (3 years), and long- (5 years) term. We calculated pooled relative risks (RRs) with 95% confidence intervals (CIs). Heterogeneity was quantified with I²-statistics.

Results: Based on the analysis of 1,515 patients from three articles, SO increased overall mortality compared to non-SO at short-, intermediate-, and long-term follow-up (RR = 2.06, 95% CI: 1.28-3.33; RR = 1.67, 95% CI: 1.10-2.51; and RR = 2.08, 95% CI: 1.10-3.93, respectively) without significant between-study heterogeneity for the short- and intermediate- term (I² = 0.0% for both) and considerable heterogeneity for long-term follow-up (I² = 81.1%).

Conclusion: Pre-transplant SO proved to be a risk factor after LT and was associated with two times higher mortality at short- and long- term follow-up. Since SO worsens the prognosis of patients after LT, the inclusion of body composition assessment before LT may help to plan a more individualized nutritional treatment, physiotherapy, and postoperative care and may improve morbidity and mortality.

New anthropometric and biochemical models for estimating appendicular skeletal muscle mass in male patients with cirrhosis

OBJECTIVES

The use of easily accessible methods to estimate skeletal muscle mass (SMM) in patients with cirrhosis is often limited by the presence of edema and ascites, precluding a reliable diagnosis of sarcopenia. The aim of this study was to design predictive models using variables derived from anthropometric and/or biochemical measures to estimate SMM; and to validate their applicability in diagnosing sarcopenia in patients with cirrhosis.

METHODS

Anthropometric and biochemical data were obtained from 124 male patients (18-76 y of age) with cirrhosis who also underwent dual-energy x-ray absorptiometry (DXA) and handgrip strength (HGS) assessments to identify low SMM and diagnose sarcopenia using reference cutoff values. Univariate analyses for variable selection were applied to generate predictive decision tree models for low SMM. Model accuracy for the prediction of low SMM and sarcopenia (when associated with HGS) was tested by comparison with reference cutoff values (appendicular SMM index, obtained by DXA) and clinical sarcopenia diagnoses. The prognostic value of the models for the prediction of sarcopenia and mortality at 104 wk of follow up was further tested using Kaplan-Meier graphics and Cox models.

RESULTS

The models with anthropometric variables, alone and combined with biochemical variables, showed good accuracy (0.89 [0.83; 0.94] and 0.90 [0.84; 0.95], respectively) and sensitivity (0.72 [0.56; 0.85] and 0.74 [0.59; 0.86], respectively) and excellent specificity (0.96 [0.90; 0.99] and 0.97 [0.92; 0.99], respectively) in predicting SMM. Both models showed excellent accuracy (0.94 [0.89; 0.98], good sensitivity (0.68 [0.45; 0.86]), and excellent specificity (1.00 [0.96; 1.00]) in predicting sarcopenia. The models predicted mortality in patients with sarcopenia, with the likelihood of death sixfold greater relative to patients not predicted to have sarcopenia.

CONCLUSIONS

Our simple and inexpensive models provided a practical and safe approach to diagnosing sarcopenia patients with cirrhosis along with an estimate of their mortality risk when other reference methods are unavailable.

Serial Observations of Muscle and Fat Mass as Prognostic Factors for Deceased Donor Liver Transplantation

Objective

Muscle depletion in patients undergoing liver transplantation affects the recipients' prognosis and therefore cannot be overlooked. We aimed to evaluate whether changes in muscle and fat mass during the preoperative period are associated with prognosis after deceased donor liver transplantation (DDLT).

Materials and Methods

This study included 72 patients who underwent DDLT and serial computed tomography (CT) scans. Skeletal muscle index (SMI) and fat mass index (FMI) were calculated using the muscle and fat area in CT performed 1 year prior to surgery (1 yr Pre-LT), just before surgery (Pre-LT), and after transplantation (Post-LT). Simple aspects of serial changes in muscle and fat mass were analyzed during three measurement time points. The rate of preoperative changes in body composition parameters were calculated (preoperative ΔSMI [%] = [SMI at Pre-LT − SMI at 1 yr Pre-LT] / SMI at Pre-LT × 100; preoperative ΔFMI [%] = [FMI at Pre-LT − FMI at 1 yr Pre-LT] / FMI at Pre-LT × 100) and assessed for correlation with patient survival.

Results

SMI significantly decreased during the preoperative period (mean preoperative ΔSMI, −13.04%, p < 0.001). In the multivariable analysis, preoperative ΔSMI (p = 0.016) and model for end-stage liver disease score (p = 0.011) were independent prognostic factors for overall survival. The mean survival time for patients with a threshold decrease in the preoperative ΔSMI (≤ −30%) was significantly shorter than for other patients (p = 0.007). Preoperative ΔFMI was not a prognostic factor but FMI increased during the postoperative period (p = 0.009) in all patients.

Conclusion

A large reduction in preoperative SMI was significantly associated with reduced survival after DDLT. Therefore, changes in muscle mass during the preoperative period can be considered as a prognostic factor for survival after DDLT.

Impact of Malnutrition on Outcomes in Patients Undergoing Transjugular Intrahepatic Portosystemic Shunt Insertion

BACKGROUND

Malnutrition is common in patients with cirrhosis and is associated with poor outcomes after hepatic resection and liver transplantation. Transjugular intrahepatic portosystemic shunt (TIPS) is performed for complications of cirrhosis.

AIM

To assess the impact of malnutrition on TIPS outcomes.

METHODS

A retrospective analysis was performed using the Healthcare Cost and Utilization Project: National Inpatient Sample database for TIPS procedures from 2005 to 2014. The primary end point was in-hospital mortality. The association of specific malnutrition diagnostic codes and race-ethnicity on mortality was evaluated with survey-weighted logistic regression adjusted for age, gender, admission type, insurance payer, hospital region, comorbidities, and length of stay (LOS).

RESULTS

From 2005 to 2014, an estimated 53,207 (95% CI 49,330-57,085) admissions with TIPS occurred. A diagnosis of malnutrition was present in 11%. In-hospital death post-TIPS occurred in 15.0% versus 10.7% (p value < 0.001) of patients with and without malnutrition, respectively. Patients with malnutrition had longer post-procedural LOS (median 6.7 vs. 2.9 days, p value < 0.001) and greater total hospital charges (median $144,752 vs. $79,781, p value < 0.001) and were more likely to be discharged to a skilled nursing facility (21.6% vs. 9.7%) than patients without malnutrition. Patients with malnutrition had increased odds of mortality (OR 1.31, 95% CI 1.07, 1.59) compared to patients with no malnutrition.

CONCLUSION

Malnutrition was associated with worse outcomes after TIPS. Further research is needed to understand the mechanism of malnutrition in post-procedure outcomes and the ability of interventions for nutritional optimization to improve outcomes.

Impact of sarcopenia on mortality in patients undergoing liver re-transplantation

BACKGROUND

Sarcopenia, which is a loss of skeletal muscle mass, has been reported to increase post-transplant mortality and morbidity in patients undergoing the first liver transplant. Cross-sectional imaging modalities typically determine sarcopenia in patients with cirrhosis by measuring core abdominal musculatures. However, there is limited evidence for sarcopenia related outcomes in patients undergoing liver re-transplantation (re-OLT).

AIM

To evaluate the risk of mortality in patients with pre-existing sarcopenia following liver re-OLT.

METHODS

This is a retrospective study of all adult patients who had undergone a liver re-OLT at the University of Nebraska Medical Center from January 1, 2007 to January 1, 2017. We divided patients into sarcopenia and no sarcopenia groups. “TeraRecon AquariusNet 4.4.12.194” software was used to evaluate computed tomography or magnetic resonance imaging of the patients done within one year prior to their re-OLT, to calculate the Psoas muscle area at L3-L4 intervertebral disc. We defined cutoffs for sarcopenia as < 1561 mm² for males and < 1464 mm² for females. The primary outcome was to compare 90 d, one, and 5-year survival rates. We also compared complications after re-OLT, length of stay, and re-admission within 30 d. Survival analysis was performed with Kaplan-Meier survival analysis. Continuous variables were evaluated with Wilcoxon rank-sum tests. Categorical variables were evaluated with Fisher’s exact tests.

RESULTS

Fifty-seven patients were included, 32 males: 25 females, median age 50 years. Two patients were excluded due to incomplete information. Overall, 47% (26) of patients who underwent re-OLT had sarcopenia. Females were found to have significantly more sarcopenia than males (73% vs 17%, P < 0.001). Median model for end stage liver disease at re-OLT was 28 in both sarcopenia and no sarcopenia groups. Patients in the no sarcopenia group had a trend of longer median time between the first and second transplant (36.5 mo vs 16.7 mo). Biological markers, outcome parameters, and survival at 90 d, 1 and 5 years, were similar between the two groups. Sarcopenia in re-OLT at our center was noted to be twice as common (47%) as historically reported in patients undergoing primary liver transplantation.

CONCLUSION

Overall survival and outcome parameters were no different in those with and without the evidence of sarcopenia after re-OLT.

Clinical impact of sarcopenia assessment in patients with hepatocellular carcinoma undergoing treatments

Changes in body composition are associated with poor outcomes in cancer patients including hepatocellular carcinoma (HCC). Sarcopenia, defined as the loss of skeletal muscle mass, quality and function, has been associated with a higher rate of complications and recurrences in patients with cirrhosis and HCC. The assessment of patient general status before HCC treatment, including the presence of sarcopenia, is a key-point for achieving therapy tolerability and to avoid short- and long-term complications leading to poor patients' survival. Thus, we aimed to review the current literature evaluating the role of sarcopenia assessment related to HCC treatments and to critically provide the clinicians with the most recent and valuable evidence. As a result, sarcopenia can be predictive of poor outcomes in patients undergoing liver resection, transplantation and systemic therapies, offering the chance to clinicians to improve the muscular status of these patients, especially those with high-grade sarcopenia at high risk of mortality. Further studies are needed to clarify the predictive value of sarcopenia in other HCC treatment settings and to evaluate its role as an additional staging tool for identifying the most appropriate treatment. Besides, interventional studies aiming at increasing the skeletal muscle mass for reducing complications and increasing the survival in patients with HCC are needed.

Sarcopenia is a useful risk stratification tool to prognosticate splenic abscess patients in the emergency department

BACKGROUND/PURPOSE

Splenic abscess is a life-threatening surgical emergency which requires early diagnosis and intervention to maximize patient outcomes. This can be achieved through accurate risk stratification in the emergency department (ED). Sarcopenia refers to an age-related loss of skeletal muscle mass and strength that is accompanied by major physiologic and clinical ramifications, and often signifies decreased physiologic reserves. It is associated with poor clinical outcomes in sepsis, acute respiratory failure, oncological surgery, and liver transplantation. This study evaluates the utility of sarcopenia as a radiological stratification tool to predict in-hospital mortality of splenic abscess patients in the ED. This will assist emergency physicians, internists and surgeons in rapid risk stratification, assessing treatment options, and communicating with family members.

METHODS

99 adult patients at four training and research hospitals who had undergone an abdominal contrast computed tomography scan in the ED with the final diagnosis of splenic abscess from January 2004 to November 2017 were recruited. Evaluation for sarcopenia was performed via calculating the psoas cross-sectional area at the level of the third lumbar vertebra and normalising for height, before checking it against pre-defined values. Univariate analyses were used to evaluate the differences between survivors and non-survivors. Sensitivity, specificity, and predictive values of the presence of sarcopenia in predicting in-hospital mortality were calculated. Kaplan-Meier methods, log-rank test, and Cox proportional hazards model were also performed to examine survival between groups with sarcopenia versus non-sarcopenia.

RESULTS

Splenic abscess patients with sarcopenia were 7.56 times more at risk of in-hospital mortality than those without sarcopenia (multivariate-adjusted HR: 7.56; 95% CI: 1.55-36.93). Presence of sarcopenia was found to have 84.62% sensitivity and 96.49% negative predictive value in predicting mortality.

CONCLUSION

Sarcopenia is associated with poor prognoses of in-hospital mortality in patients with splenic abscess presenting to the ED. We recommend its use in the ED to rapidly risk stratify and predict outcome to guide treatment strategies.

Use of Skeletal Muscle Index as a Predictor of Wait-List Mortality in Patients With End-Stage Liver Disease

The aim of this study is to validate a proposed definition of sarcopenia in predicting wait-list mortality. We retrospectively evaluated 355 adults (age ≥18 years) with cirrhosis listed for first-time LT from January 1, 2010, to April 1, 2018 from our center. Demographic, laboratory, and outcome data were collected in conjunction with computed tomography scans performed within 3 months of listing. Using imaging analysis software, the skeletal muscle index (SMI), which is a marker for sarcopenia-related mortality, was calculated. A survival analysis was performed to evaluate the association of the proposed sarcopenia definition of SMI <50 cm² /m² for men or <39 cm² /m² for women with wait-list mortality or delisting. Median SMI was 54.1 cm² /m² (range, 47-60 cm² /m² ). A total of 61 (17.2%) patients exhibited sarcopenia according to the proposed threshold, and 24.6% (57/232) of men were sarcopenic compared with 3.3% (4/123) of women (P < 0.001). Mean (standard deviation [SD]) SMI was also higher for men (56.6 ± 9.6 cm² /m² ) than for women (50.7 ± 8.0 cm² /m² ; P < 0.001). Median follow-up time among patients was 2.1 months (0-12 months), and 30 events were observed (hazard ratio, 0.98; 95% confidence interval, 0.95-1.02; P = 0.41). There was no statistically significant difference in time on the waiting list between patients with and without sarcopenia (P = 0.89) as defined at the threshold. Using the prespecified definitions of sarcopenia based on SMI, there was no statistically significant difference in mortality and delisting from the transplant waiting list between patients with and without sarcopenia in this population. Practice and region-specific patterns for pretransplant selection and median Model for End-Stage Liver Disease at transplant may affect SMI as a predictor of wait-list mortality.

Automated Measurements of Muscle Mass Using Deep Learning Can Predict Clinical Outcomes in Patients With Liver Disease

INTRODUCTION

There is increasing recognition of the central role of muscle mass in predicting clinical outcomes in patients with liver disease. Muscle size can be extracted from computed tomography (CT) scans, but clinical implementation will require increased automation. We hypothesize that we can achieve this by using artificial intelligence.

METHODS

Using deep convolutional neural networks, we trained an algorithm on the Reference Analytic Morphomics Population (n = 5,268) and validated the automated methodology in an external cohort of adult kidney donors with a noncontrast CT scan (n = 1,655). To test the clinical usefulness, we examined its ability to predict clinical outcomes in a prospectively followed cohort of patients with clinically diagnosed cirrhosis (n = 254).

RESULTS

Between the manual and automated methodologies, we found excellent inter-rater agreement with an intraclass correlation coefficient of 0.957 (confidence interval 0.953-0.961, P < 0.0001) in the adult kidney donor cohort. The calculated dice similarity coefficient was 0.932 ± 0.042, suggesting excellent spatial overlap between manual and automated methodologies. To assess the clinical usefulness, we examined its ability to predict clinical outcomes in a cirrhosis cohort and found that automated psoas muscle index was independently associated with mortality after adjusting for age, gender, and child's classification (P < 0.001).

DISCUSSION

We demonstrated that deep learning techniques can allow for automation of muscle measurements on clinical CT scans in a diseased cohort. These automated psoas size measurements were predictive of mortality in patients with cirrhosis showing proof of principal that this methodology may allow for wider implementation in the clinical arena.

Preoperative Assessment of Muscle Mass Using Computerized Tomography Scans to Predict Outcomes Following Orthotopic Liver Transplantation

BACKGROUND

Sarcopenia is an established risk factor predicting survival in chronically ill and trauma patients. We herein examine the assessment and clinical implication of sarcopenia in liver transplantation (LT).

METHODS

Computerized tomography scans from 172 patients waitlisted for LT were analyzed by applying 6 morphometric muscle scores, including 2 density indices (psoas density [PD] and skeletal muscle density [SMD]) and 4 scores based on muscle area (total psoas area, psoas muscle index, skeletal muscle area, and skeletal muscle index).

RESULTS

The prevalence of sarcopenia in our cohort ranged from 7.0% to 37.8%, depending on the score applied. Only sarcopenia as defined by the density indices PD and SMD (but not total psoas area, psoas muscle index, skeletal muscle area, or skeletal muscle index) revealed clinical relevance since it correlates significantly with postoperative complications (≥Grade III, Clavien-Dindo classification) and sepsis. Furthermore, sarcopenia predicted inferior patient and graft survival, with low muscle density (PD: <38.5 HU or SMD: <30 HU) representing an independent risk factor in a multivariate regression model (P < 0.05). Importantly, the widely used Eurotransplant donor risk index had a predictive value in nonsarcopenic patients but failed to predict graft survival in patients with sarcopenia.

CONCLUSIONS

Sarcopenia revealed by low muscle density correlates with major complications following LT and acts as an independent predictor for patient and graft survival. Therefore, the application of a simple computerized tomography-morphologic index can refine an individual recipient's risk estimate in a personalized approach to transplantation.

A Sex-Stratified Prognostic Nomogram Incorporating Body Compositions for Long-Term Mortality in Cirrhosis

BACKGROUND

Alterations in body compositions are related to poor outcomes and the presence of complications in cirrhosis. However, no predictive tools combining all these anthropometric parameters are applicable in the clinical setting. We aimed to clarify the potential utility of body compositions and develop a nomogram incorporating any independent factor for prognosticating long-term mortality in cirrhosis.

METHODS

A total of 414 patients were randomized into primary (n = 274) and validation (n = 140) cohorts. X-tile was performed to identify optimal cut points for stratifying participants. Multivariate Cox regression was performed, and nomogram incorporating body compositions were generated. The utility of developed models was evaluated by Harrell concordance index (C-index), calibration curve, and decision curve analysis (DCA).

RESULTS

Stratifying by X-tilederived cut points, low skeletal muscle index (myopenia), high intramuscular adipose tissue content (myosteatosis), and the ratio of high visceral to subcutaneous adipose tissue area (adiposity) was independently associated with 3-year mortality. A sex-stratified nomogram incorporating anthropometric indices and clinical factors resulted in moderate discriminative accuracy, with a C-index of 0.787 (95% CI, 0.736-0.838) and 0.789 (95% CI, 0.727-0.851) in males and females, respectively. The calibration curve showed predictive survival corresponding optimally with the actual outcomes. Our models were feasible in the clinical settings based on DCA. Similar results were observed in the validation cohort. Additionally, participants could be classified into 3 distinct risk groups by the nomogram.

CONCLUSIONS

Our proposed nomogram embedding body compositions rendered an individualized predictive tool for long-term mortality in cirrhosis.

An interdisciplinary approach to the older transplant patient: strategies for improving clinical outcomes

PURPOSE OF REVIEW

To describe the latest investigations into the role of frailty and assessment of other aging-related issues in the solid organ transplant candidate and recipient. This information is relevant for all involved in the care of transplant patients, but is especially relevant in infectious diseases, given the increased burden of infection seen in older and frailer patients.

RECENT FINDINGS

The Fried Frailty Phenotype (FFP) and Short Performance Physical Battery (SPPB) are well validated tools for measuring frailty in older adults. Recently, these frailty tools have also been used to predict a range of clinical outcomes in adults with endstage organ disease undergoing advanced therapies including mechanical circulatory device (MCSD) or transplantation including death on the waiting list, length of hospital stay, need for readmission, infection, and death. Frailty may also be estimated by chart review and comorbidity assessment. Other aging-related evaluations of interest are cognitive function, sarcopenia, and nutritional status. The strength of association for each tool varies by the type of end organ disease, although there are many findings in common across organ types.

SUMMARY

As trends in the aging of the population continue to impact transplant and MCSD candidates and recipients, it is increasingly important for providers to be cognizant of the methods for assessment of aging-associated dysfunction including frailty and sarcopenia.

Paediatric reference values for total psoas muscle area

BACKGROUND

Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross-sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3-4 and L4-5.

METHODS

In this cross-sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1-16 years who required abdominal cross-sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (tPMA) at levels L3-4 and L4-5 were measured in square millimetres (mm² ) as the sum of left and right PMA. Age-specific and sex-specific tPMA percentile curves were modelled using quantile regression.

RESULTS

Computed tomography images from 779 children were included. Values of tPMA at L4-5 were significantly larger than at L3-4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, tPMA 50th percentile values ranged from 365 to 2336 mm² at L3-4 and from 447 to 2704 mm² for L4-5. Amongst boys, 50th percentile values for tPMA ranged between 394 and 3050 mm² at L3-4 and from 498 to 3513 mm² at L4-5. Intraclass correlation coefficients were excellent at L3-4 (0.97, 95% CI 0.94 to 0.981) and L4-5 (0.99, 95% CI 0.986 to 0.995). Weight and tPMA were correlated, stratified by sex for boys (L3-4 r = 0.90; L4-5 r = 0.90) and for girls (L3-4 r = 0.87; L4-5 r = 0.87). An online application was subsequently developed to easily calculate age-specific and sex-specific z-scores and percentiles.

CONCLUSIONS

We provide novel paediatric age-specific and sex-specific growth curves for tPMA at intervertebral L3-4 and L4-5 levels for children between the ages of 1-16 years. Together with an online tool (https://ahrc-apps.shinyapps.io/sarcopenia/), these tPMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.

Risk stratification for early bacteremia after living donor liver transplantation: a retrospective observational cohort study

BACKGROUND

This study investigated perioperative clinical risk factors for early post-transplant bacteremia in patients undergoing living donor liver transplantation (LDLT). Additionally, postoperative outcomes were compared between patients with and without early post-transplant bacteremia.

METHODS

Clinical data of 610 adult patients who underwent elective LDLT between January 2009 and December 2018 at Seoul St. Mary's Hospital were retrospectively collected. The exclusion criteria included overt signs of infection within 1 month before surgery. A total of 596 adult patients were enrolled in this study. Based on the occurrence of a systemic bacterial infection after surgery, patients were classified into non-infected and infected groups.

RESULTS

The incidence of bacteremia at 1 month after LDLT was 9.7% (57 patients) and Enterococcus faecium (31.6%) was the most commonly cultured bacterium in the blood samples. Univariate analysis showed that preoperative psoas muscle index (PMI), model for end-stage disease score, utility of continuous renal replacement therapy (CRRT), ascites, C-reactive protein to albumin ratio, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, and sodium level, as well as intraoperative post-reperfusion syndrome, mean central venous pressure, requirement for packed red blood cells and fresh frozen plasma, hourly fluid infusion and urine output, and short-term postoperative early allograft dysfunction (EAD) were associated with the risk of early post-transplant bacteremia. Multivariate analysis revealed that PMI, the CRRT requirement, the NLR, and EAD were independently associated with the risk of early post-transplant bacteremia (area under the curve: 0.707; 95% confidence interval: 0.667-0.745; p < 0.001). The overall survival rate was better in the non-infected patient group. Among patients with bacteremia, anti-bacterial treatment was unable to resolve infection in 34 patients, resulting in an increased risk of patient mortality. Among the factors included in the model, EAD was significantly correlated with non-resolving infection.

CONCLUSIONS

We propose a prognostic model to identify patients at high risk for a bloodstream bacterial infection; furthermore, our findings support the notion that skeletal muscle depletion, CRRT requirement, systemic inflammatory response, and delayed liver graft function are associated with a pathogenic vulnerability in cirrhotic patients who undergo LDLT.

Sarcopenia is associated with increased mortality but not complications following resection and reconstruction of sarcoma of the extremities

BACKGROUND AND OBJECTIVES

Evidence regarding the impact of sarcopenia on operative outcomes in patients with sarcoma is lacking. We evaluated the relationship between sarcopenia and postoperative complications or mortality among patients undergoing tumor excision and reconstruction. ​ METHODS: We retrospectively reviewed 145 patients treated with tumor excision and limb reconstruction for sarcoma of the extremities. Sarcopenia was defined as psoas index (PI) < 5.45 cm² /m² for men and <3.85 cm² /m² for women from preoperative axial CT. Regression analyses were used to assess the association between postoperative complications or mortality with PI, age, gender, race, body mass index, tumor histology, grade, depth, location, size, and neoadjuvant/adjuvant therapy.

RESULTS

There were 101 soft tissue tumors and 44 primary bone tumors. Sarcopenia was present in 38 patients (26%). Sarcopenic patients were older (median age: 72 vs 59 years, P = .0010) and had larger tumors (86.5%, >5 cm vs 77.7%, P = .023). Seventy-three patients experienced complications (51%) and 18 patients died within 1 year. Sarcopenia and metastatic disease were associated with increased 12-month mortality (hazard ratio [HR] = 6.68, P < .001; HR: 8.51, P < .001, respectively) but not complications (HR 1.45, P = .155, odds ratio, 1.32, P = .426, respectively).

CONCLUSIONS

Sarcopenia and metastatic disease were independently associated with postoperative mortality but no complications following surgery.

Systematic review with meta-analysis: Nutritional screening and assessment tools in cirrhosis

BACKGROUND & AIMS

Disease-related malnutrition is common in cirrhosis. Multiple studies have evaluated nutritional screening tools (NSTs, rapid bedside tests targeting who needs assessment) and nutritional assessment tools (NATs, used in diagnosing malnutrition) as predictors of clinical outcome in this population. We performed a systematic review and meta-analysis of this literature with the aim of summarising the varying definitions of malnutrition across studies, the available evidence for NSTs and the ability of NSTs and NATs to predict clinical outcomes in cirrhosis.

METHODS

The primary outcome measures were pre- and post-transplant mortality with a range of secondary outcomes. Inclusion: cirrhosis over age 16. Exclusion: >25% with hepatocellular carcinoma, primarily laboratory test-based NATs or lack of screening, assessment or outcome criteria.

RESULTS

Eight thousand eight hundred fifty patients were included across 47 studies. Only 3 studies assessed NSTs. Thirty-two definitions for malnutrition were utilised across studies. NATs predicted pre-transplant mortality in 69% of cases that were assessed with a risk ratio (RR) of 2.38 (95% CI 1.96-2.89). NATs were prognostic for post-transplant mortality only 28% of the times they were assessed, with a RR of 3.04 (95% CI 1.51-6.12).

CONCLUSIONS

The cirrhosis literature includes limited data on nutrition screening and multiple definitions for what constitutes malnutrition using NATs. Despite this discordance, it is clear that malnutrition is a valuable predictor of pre-transplant mortality almost regardless of how it is defined. We require clinical and research consensus around the definition of malnutrition and the accepted processes and cut-points for nutrition screening and assessment in cirrhosis.

Myosteatosis to predict inferior perioperative outcome in patients undergoing orthotopic liver transplantation

Muscle wasting and alterations of body composition are linked to clinical outcomes in numerous medical conditions. The role of myosteatosis in posttransplant outcomes remains to be determined. Here we investigated skeletal muscle mass and myosteatosis as prognostic factors in patients undergoing orthotopic liver transplantation (OLT). The data of 225 consecutive OLT recipients from a prospective database were retrospectively analyzed (May 2010-December 2017). Computed tomography-based skeletal-muscle-index (muscle mass), visceral-fat-area (visceral adiposity), and mean skeletal-muscle-radiation-attenuation (myosteatosis) were calculated using a segmentation tool. Cut-off values of myosteatosis resulted in a good stratification of patients into low- and high-risk groups in terms of morbidity (Clavien-Dindo ≥3b). Patients with myosteatosis had significantly higher complication rates (90-day Comprehensive Complication Index 68 ± 32 vs 44 ± 30, P < .001) and also displayed significantly longer intensive care (18 ± 25 vs 11 ± 21 days, P < .001) and hospital stay (56 ± 55 vs 33 ± 24 days, P < .001). Estimated costs were 44% higher compared to patients without myosteatosis. Multivariable analysis identified myosteatosis as an independent prognostic factor for major morbidity (odds ratio: 2.772, confidence interval: 1.516-5.066, P = .001). Adding myosteatosis to the well-established Balance-of-Risk-(BAR) score resulted in an increased prognostic value compared to the original BAR score. Myosteatosis may be a useful parameter to predict perioperative outcome in patients undergoing OLT, supporting the role of muscle quality (myosteatosis) over quantity (muscle mass) in this setting.

Peri-transplant management of nonalcoholic fatty liver disease in liver transplant candidates

The incidence of non-alcoholic fatty liver disease (NAFLD) is rapidly growing, affecting 25% of the world population. Non-alcoholic steatohepatitis (NASH) is the most severe form of NAFLD and affects 1.5% to 6.5% of the world population. Its rising incidence will make end-stage liver disease (ESLD) due to NASH the number one indication for liver transplantation (LT) in the next 10 to 20 years, overtaking Hepatitis C. Patients with NASH also have a high prevalence of associated comorbidities such as type 2 diabetes, obesity, metabolic syndrome, cardiovascular disease, and chronic kidney disease (CKD), which must be adequately managed during the peritransplant period for optimal post-transplant outcomes. The focus of this review article is to provide a comprehensive overview of the unique challenges these patients present in the peritransplant period, which comprises the pre-transplant, intraoperative, and immediate postoperative periods.

Assessment of magnetic resonance imaging derived fat fraction as a sensitive and reliable predictor of myosteatosis in liver transplant recipients

BACKGROUND

Measures of skeletal muscle abnormalities are rapidly emerging as independent predictors of outcomes after liver transplantation (LT). We describe a simple, novel assessment of myosteatosis acquired prior to liver transplantation using Magnetic Resonance Imaging (MRI) derived fat fraction.

METHODS

A retrospective longitudinal cohort study included clinical and biochemical data from patients who underwent liver transplantation at our institution between Feb 2008 and Aug 2014. Patients transplanted for a diagnosis of hepatocellular carcinoma were excluded from the study. The fat fraction of erector spinae muscles was estimated using MRI at the level where muscle volume was highest, with myosteatosis defined at a cut-off value of 0.8.

RESULTS

180 patients were included. At baseline, those with myosteatosis were, on average, older, more likely to be female, and more likely to receive a multi-organ transplant (p < 0.05). Patients with pre-transplant myosteatosis, as delineated by MRI derived fat fraction, also had increased length of hospital stay.

CONCLUSION

This preliminary study suggests myosteatosis, as measured by fat fraction on MRI prior to LT, may be associated with increased graft loss and mortality after transplant.

Radiologic Assessment of Muscle and Fat Stores in Long-Term Type I Diabetics Referred for Pancreas Transplant Compared to Healthy Controls

Type 1 diabetes (DM1) is associated with loss of skeletal muscle and bone mass and may affect body fat stores. This study employs computed tomography (CT) scans to assess the body composition of DM1 patients referred for pancreas transplant compared to healthy controls. A 1:1 case-control design matched study patients with otherwise healthy patients from the trauma database. Matching criteria included age ± 5 years, gender, and body mass index (BMI) ± 2kg/m². Nutrition variables included serum albumin and protein levels, BMI, and CT measures of muscle mass and fat stores. There were 22 subjects and 22 controls (median DM1 duration 24 years). DM1 patients had less muscle mass and less subcutaneous fat but no difference in visceral fat. Patients with the greatest muscle deficit were those with DM1 greater than 20 years and those younger than age 40. DM1 patients maintain similar BMI and protein levels compared to healthy controls but have marked deficits of muscle and subcutaneous fat. These results inform the nutritional management of DM1 patients and quantify the muscle and fat deficits present in these patients. At highest risk are young patients and those with duration of DM1 over 20 years.

Association of Chest CT-Based Quantitative Measures of Muscle and Fat with Post-Lung Transplant Survival and Morbidity: A Single Institutional Retrospective Cohort Study in Korean Population

OBJECTIVE

Abnormal body composition is an important modifiable risk factor in lung transplantation. Therefore, precise quantification of different body components, including muscle and fat, may play an important role in optimizing outcomes in lung transplant patients. The purpose of the study was to investigate the prognostic significance of muscle and subcutaneous fat mass measured on chest CT with regard to lung transplantation survival and other post-transplant outcomes.

MATERIALS AND METHODS

The study population included 45 consecutive adult lung transplant recipients (mean age of 47.9 ± 12.1 years; 31 males and 14 females) between 2011 and 2017. Preoperative cross-sectional areas of muscle and subcutaneous fat were semi-automatically measured on axial CT images at the level of the 12th thoracic vertebra (T12). Additional normalized indexed parameters, adjusted for either height or weight, were obtained. Associations of quantitative parameters with survival and various other post-transplant outcomes were evaluated.

RESULTS

Of the 45 patients included in the present study, 10 mortalities were observed during the follow-up period. Patients with relative sarcopenia (RS) classified based on height-adjusted muscle area with a cut-off value of 28.07 cm²/m² demonstrated worse postoperative survival (log-rank test, p = 0.007; hazard ratio [HR], 6.39:1) despite being adjusted for age, sex, and body mass index (HR, 8.58:1; p = 0.022). Weight-adjusted parameters of muscle area were negatively correlated with duration of ventilator support (R = -0.54, p < 0.001) and intensive care unit (ICU) stay (R = -0.33, p = 0.021).

CONCLUSION

Patients with RS demonstrate worse survival after lung transplantation that those without RS. Additionally, quantitative parameters of muscles measured at the T12 level on chest CT were associated with the duration of post-lung transplant ventilator support and duration of stay in the ICU.

Skeletal muscle size, function, and adiposity with lifelong aerobic exercise

We examined the influence of lifelong aerobic exercise on skeletal muscle size, function, and adiposity. Young exercisers [YE; n = 20, 10 women (W), 25 ± 1 yr], lifelong exercisers (LLE; n = 28, 7 W, 74 ± 2 yr), and old healthy nonexercisers (OH; n = 20, 10 W, 75 ± 1 yr) were studied. On average, LLE exercised 5 days/wk for 7 h/wk over the past 52 ± 1 yr. The LLE men were subdivided by exercise intensity [Performance (LLE-P), n = 14; Fitness (LLE-F), n = 7]. Upper and lower leg muscle size and adiposity [intermuscular adipose tissue (IMAT)] were determined via MRI, and quadriceps isotonic and isometric function was assessed. For the quadriceps, aging decreased muscle size, isotonic and isometric strength, contraction velocity (men only), and power (P < 0.05). In women, LLE did not influence muscle size or function. In men, LLE attenuated the decline in muscle size and isometric strength by ~50% (P < 0.05). LLE did not influence other aspects of muscle function, nor did training intensity influence muscle size or function. For the triceps surae, aging decreased muscle size only in the women, whereas LLE (both sexes) and training intensity (LLE men) did not influence muscle size. In both sexes, aging increased thigh and calf IMAT by ~130% (P < 0.05), whereas LLE attenuated the thigh increase by ~50% (P < 0.05). In the LLE men, higher training intensity decreased thigh and calf IMAT by ~30% (P < 0.05). In summary, aging and lifelong aerobic exercise influenced muscle size, function, and adipose tissue infiltration in a sex- and muscle-specific fashion. Higher training intensity throughout the life span provided greater protection against adipose tissue infiltration into muscle.NEW & NOTEWORTHY This is the first study to examine skeletal muscle size, function, and adiposity in women and men in their eighth decade of life that have engaged in lifelong aerobic exercise. The findings reveal sex and upper and lower leg muscle group-specific benefits related to skeletal muscle size, function, and adiposity and that exercise intensity influences intermuscular adiposity. This emerging cohort will further our understanding of the health implications of maintaining exercise throughout the life span.

Sarcopenia in Cirrhosis: Looking Beyond the Skeletal Muscle Loss to See the Systemic Disease

Sarcopenia is a common complication of cirrhosis and is defined as a progressive and generalized loss of skeletal muscle mass, strength, and function. Sarcopenia is associated with poor prognosis and increased mortality. How sarcopenia and muscle wasting relate to such poor outcomes requires looking beyond the overt muscle loss and at this entity as a systemic disease that affects muscles of vital organs including cardiac and respiratory muscles. This review explores the pathophysiological pathways and mechanisms that culminate in poor outcomes associated with sarcopenia. This provides a launching pad to identify potential targets for therapeutic intervention and optimization to improve patient outcomes.

Prevalence and outcomes of fragility: a frailty-inflammation phenotype in children with chronic kidney disease

BACKGROUND

Frailty is a condition of decreased physiologic reserve and increased vulnerability to stressors. Frailty in combination with inflammation has been associated with increased mortality risk in adults with advanced chronic kidney disease (CKD). This study aimed to investigate prevalence and outcomes associated with a frailty-inflammation phenotype, or "fragility," in children with CKD.

METHODS

We analyzed 557 children (age 6-19 years, eGFR 30-90 ml/min/1.73 m²) from the Chronic Kidney Disease in Children (CKiD) study. Based on adult models, the CKiD fragility model included four indicators: (1) suboptimal growth/weight gain (BMI < 5th percentile-for-height-age, deceleration ≥ 10 BMI-for-height-age percentiles/1 year, height-for-age percentile < 3rd or deceleration ≥ 10 height percentiles/1 year); (2) low muscle mass (mid-upper-arm circumference < 5th percentile or deceleration ≥ 10 percentiles/1 year); (3) fatigue (parent/child report); (4) inflammation (CRP > 3 mg/l). Logistic regression was used to evaluate association of fragility indicators with three adverse outcomes: frequent infection (> 1 per year/3 years), hospitalization (any), and rapid CKD progression (decline in eGFR > 30% or initiation of renal replacement therapy within 3 years).

RESULTS

Prevalence of fragility indicators 1 year after study entry were 39% (suboptimal growth/weight gain), 62% (low muscle mass), 29% (fatigue), and 18% (inflammation). Prevalence of adverse outcomes during the subsequent 3 years were 13% (frequent infection), 22% (hospitalization), and 17% (rapid CKD progression). Children with ≥ 3 fragility indicators had 3.16-fold odds of frequent infection and 2.81-fold odds of hospitalization, but did not have rapid CKD progression.

CONCLUSIONS

A fragility phenotype, characterized by the presence of ≥ 3 indicators, is associated with adverse outcomes, including infection and hospitalization in children with CKD.