Persistence of Sarcopenia After Pediatric Liver Transplantation Is Associated With Poorer Growth and Recurrent Hospital Admissions

Preservation of fat mass at the expense of lean mass in children with end-stage chronic liver disease

BACKGROUND

Sarcopenia predicts morbidity and mortality in end-stage chronic liver disease (ESCLD). Here, we describe changes in body composition in children with ESCLD before and after liver transplantation (LT).

METHODS

Retrospective analysis of whole body DXA scans performed before and after LT over 4 years. Appendicular and whole-body fat mass and lean mass were expressed as fat mass (FMI) and lean mass (LMI) index z-scores. Sarcopenia was defined as leg LMI z-score <-1.96.

RESULTS

Eighty-three DXA scans of children before or after LT were studied. Sarcopenia had a positive correlation with weight (0.8, p < .01), height (0.48, p < .05), and BMI z-score (0.77, p < .01), as well as arm, trunk, and total mean mass indices. It correlated negatively with indices of hypersplenism: PLTs (-0.57, p < .01), Neu (-0.50, p < .05), WCC (-0.44, p < .05), and days to discharge (-0.46, p < .05). At baseline: 13/25 (52%) children were sarcopenic and stayed in the hospital after LT for longer. Eight were stunted with a higher WCC and Ne/Ly ratio. All had normal FM indices. One year after LT, 12/26 children remained sarcopenic. Seven were stunted. Two years after LT, 5/15 were sarcopenic, and 5 were stunted. Three years after LT, 1/10 was sarcopenic, and 2 were stunted. By 4 years after LT, 1/7 was sarcopenic, and the same one was stunted. FM indices remained normal.

CONCLUSIONS

Sarcopenic patients stayed longer in the hospital after LT. Lean mass indices were mostly within the normal range by 4 years after LT. 32% of children were stunted, and markers of inflammation were correlated with stunting. Fat mass was preserved at the cost of lean mass.

Diagnostic criteria, prevalence, and clinical outcomes of pediatric sarcopenia: A scoping review

BACKGROUND & AIMS

Sarcopenia, characterized by loss of muscle mass and decreased muscle strength, significantly affects adults but also influences pediatric health. However, definitions for low muscle mass, decreased strength, and sarcopenia in children are less established, impacting interventions for improving health outcomes. The objective of this scoping review is synthesize the existing literature on the diagnostic criteria, prevalence and clinical outcomes of sarcopenia.

METHODS

A scoping review, following the PRISMA extension for scoping reviews, examined pediatric sarcopenia literature until June 2023. The literature search was performed using MEDLINE and the Cochrane Central Register of Controlled Trials with the last search conducted on June 30, 2023. Criteria included studies on aged 0-20 years, covering healthy subjects, acutely ill patients, and chronic disease cases excluding specific conditions like neuromuscular diseases or prematurity.

RESULTS

Initial search found 503 studies, finally, we included 56 studies. Most studies diagnosed sarcopenia using skeletal muscle mass indicators like total psoas muscle area from Computed Tomography or Magnetic Resonance Imaging. Around half of the longitudinal studies highlighted sarcopenia as a risk factor for various clinical outcomes, predominantly in hospitalized patients. However, cutoff values for sarcopenia indicators lacked consistency, with studies employing diverse percentile-based measurements or z-scores.

CONCLUSION

Pediatric sarcopenia diagnosis primarily relies on skeletal muscle mass, with identified links to future clinical outcomes in specific conditions. The lack of standardized cutoffs for sarcopenia indicators underscores the necessity for age, gender, and race-specific cutoff values derived from studies establishing reference values for muscle mass and strength across diverse pediatric populations.

Sarcopenia with decreased total psoas muscle area in children with high-risk neuroblastoma

BACKGROUND

We calculated psoas muscle area (PMA) z-scores in high-risk neuroblastoma patients undergoing treatment to examine the clinical significance of sarcopenia in this cohort.

METHODS

We analyzed retrospective data from patients aged 0-18 who were diagnosed with abdominal neuroblastoma between 2005 and 2019 at Samsung Medical Center. Patients categorized as high-risk undergone induction chemotherapy, neuroblastoma excision, and tandem high-dose chemotherapy with autologous stem cell transplantation (HDCT/auto-SCT) were selected. L3-4 lumbar levels on axial CT images were identified and we measured the areas of the left and right psoas muscles to determine tPMA. Total PMA z-scores were calculated using an open online tool.

RESULTS

There were 45 boys and 25 girls with a mean age of 3.86 years. CT images taken at initial diagnosis and after tandem HDCT/auto-SCT were selected to calculate tPMA z-scores. Mean elapsed time between the two measurements was 12.91 ± 1.73 months. Mean tPMA z-score significantly decreased from -0.21 ± 1.29 to -0.66 ± 0.97 (p = 0.022). Length of hospital stay was significantly longer in the group of patients whose tPMA z-scores decreased by more than .45 (177.62 ± 28.82 days vs. 165.75 ± 21.34 days, p = 0.049). Presence of sarcopenia at initial diagnosis was a significant risk factor for bacterial infection during neuroblastoma treatment.

CONCLUSION

tPMA z-scores in high-risk neuroblastoma patients decreased significantly following a treatment regimen that included induction chemotherapy, tumor resection surgery, and HDCT/auto-SCT. A greater decrease in tPMA z-score was associated with longer hospital stay during treatment.

Predictors for pathological bone fractures in children undergoing liver transplantation: A retrospective cohort study

BACKGROUND

Hepatic osteodystrophy refers to bone disorders associated with chronic liver disease, including children undergoing liver transplantation (LT). The aim of this study was to quantify the prevalence of pathological fractures (PF) in children before and after LT and to identify associated factors for their occurrence.

METHODS

Children aged 0-18 years who underwent LT from 1/2005 to 12/2020 were included in this retrospective study. Data on patient demographics, types and anatomical locations of fracture and biological workups were extracted. Variables were assessed at 3 time points: T - 1 at the moment of listing for LT; T0 at the moment of LT and T + 1 at 1-year post-LT.

RESULTS

A total of 105 children (49 [47%] females) were included in this study. Median age at LT was 19 months (range 0-203). Twenty-two patients (21%) experienced 65 PF, 11 children before LT, 10 after LT, and 1 before and after LT. The following variables were observed as associated with PF: At T - 1, low weight and height z-scores, and delayed bone age; at T0, low weight and height z-scores, high total and conjugated bilirubin; at T + 1, persistent low height z-score. Patients in the PF-group were significantly more under calcium supplementation and/or nutritional support at T - 1, T0 and T + 1.

CONCLUSION

More than one in five children needing LT sustain a PF before or after LT. Patients with low weight and height z-scores and delayed bone age are at increased risk for PF. Nutritional support remains important, even if to date it cannot fully counteract the risks of PF.

Optimizing the pediatric transplant candidate

PURPOSE OF REVIEW

Advances in pediatric transplant parallel those in adult populations; however, there remain critical unique considerations and differences that require specialized knowledge and a specific skill set to optimize care afforded to the pediatric transplant candidate. We introduce general themes regarding optimization of the transplant candidate that are unique to children.

RECENT FINDINGS

The pathologies leading to pediatric organ transplant candidacy differ from adults and a precise understanding of the physiologies and natural histories of such diseases is critical for optimized care. Regardless of etiology, comorbidities including malnutrition, sarcopenia, and developmental delay are seen and often require disease and organ specific approaches to management. Additionally, an understanding of the concepts of developmental immunology and their relevance to transplant is critical.

SUMMARY

When looking to optimize pretransplant care, awareness of the pediatric-specific challenges by the transplant community in addition to organ- and age-specific management strategies enable the best outcomes for children awaiting solid organ transplantation.

Exercise rehabilitation to treat sarcopenia in pediatric transplant populations

BACKGROUND

In adult transplant (Tx) populations, exercise rehabilitation strategies may improve sarcopenia components (muscle mass [MM], strength [MS], and physical performance [PP]). Limited data are available regarding exercise rehabilitation therapy in pediatric Tx populations.

METHODS

The purpose of this review is to critically evaluate the feasibility and impact of exercise programs (EP) that include resistance exercise (RE) on markers of sarcopenia in pediatric Tx populations. Literature searches in SCOPUS and WEB OF SCIENCE were conducted to identify studies applying EP with a RE component in pediatric populations in the Tx setting.

RESULTS

Twelve articles (2008-2022) met inclusion criteria. The exercise interventions varied in length (3 weeks-12 months), intensity (low to moderate), time pre/post Tx (0 days-5 years post Tx), age of participants (3-18 years), adherence (63%-94%), and methodologies to measure components of sarcopenia. No studies measured all three components of sarcopenia concurrently. Approximately, 60% of studies found positive effects on MS and PP. Only one pediatric study measured body composition, therefore, the effect of exercise programs with RE components on MM is unknown.

CONCLUSIONS

Exercise programs may be a beneficial treatment for sarcopenia in Tx populations, particularly in components of MS and PP. Studies measuring all three aspects of sarcopenia together in response to RE training in pediatrics remains an important gap. Studies that include body composition measurements in response to exercise are needed. Special considerations for the development of RE programs in pediatrics Tx populations are safety, supervision, engagement through family/peer involvement and incorporation of game/play-based elements.

Pediatric body composition based on automatic segmentation of computed tomography scans: a pilot study

BACKGROUND

Body composition during childhood may predispose to negative health outcomes later in life. Automatic segmentation may assist in quantifying pediatric body composition in children.

OBJECTIVE

To evaluate automatic segmentation for body composition on pediatric computed tomography (CT) scans and to provide normative data on muscle and fat areas throughout childhood using automatic segmentation.

MATERIALS AND METHODS

In this pilot study, 537 children (ages 1-17 years) who underwent abdominal CT after high-energy trauma at a Dutch tertiary center (2002-2019) were retrospectively identified. Of these, the CT images of 493 children (66% boys) were used to establish normative data. Muscle (psoas, paraspinal and abdominal wall) and fat (subcutaneous and visceral) areas were measured at the third lumbar vertebral (L3) level by automatic segmentation. A representative subset of 52 scans was also manually segmented to evaluate the performance of automatic segmentation.

RESULTS

For manually-segmented versus automatically-segmented areas (52 scans), mean Dice coefficients were high for muscle (0.87-0.90) and subcutaneous fat (0.88), but lower for visceral fat (0.60). In the control group, muscle area was comparable for both sexes until the age of 13 years, whereafter, boys developed relatively more muscle. From a young age, boys were more prone to visceral fat storage than girls. Overall, boys had significantly higher visceral-to-subcutaneous fat ratios (median 1.1 vs. 0.6, P<0.01) and girls higher fat-to-muscle ratios (median 1.0 vs. 0.7, P<0.01).

CONCLUSION

Automatic segmentation of L3-level muscle and fat areas allows for accurate quantification of pediatric body composition. Using automatic segmentation, the development in muscle and fat distribution during childhood (in otherwise healthy) Dutch children was demonstrated.

Skeletal muscle fibre morphology in childhood-insights into myopenia in pediatric liver disease

TAKE-HOME MESSAGE

Skeletal muscle morphology in healthy children changes with age. Liver disease may preferentially affect type II fibres in adults with end-stage liver disease (ESLD). More research is needed on the effects of ESLD on muscle morphology in children.

Physical function in children and adolescents pre- and 1-year post-liver transplant

BACKGROUND

Several studies describe poorer motor developmental motor outcomes post-liver transplant (LT) in younger children. Limited studies examine physical function in older children and adolescents pre- and post-LT.

METHODS

Retrospective review of standard of care physical function outcome measures pre- and 1-year post-LT in children ≥6 years at LT. Measures include: 6-minute walk test (6MWT), grip strength, Bruininks-Oseretsky Test of Motor Proficiency-2 (BOT-2) components, Physical Activity Questionnaire (PAQ), and Paediatric Quality of Life Multidimensional Fatigue Scale. Association of medical variables with outcomes was explored.

RESULTS

The study cohort included 23 (8 male, median (interquartile range) age 11.67 (8.25, 13.92) years at LT) participants. Top two primary diagnoses included biliary atresia (30.4%) and fulminant hepatic failure (21.7%). At 1-year post-LT, over one-third (36%) were overweight or obese. Compared with healthy norms, children had significantly lower pre-LT PAQ scores (p = .002), pre- and post-6MWT scores (p < .001) and post-LT BOT-2 strength and agility scores (p < .001). Pre-LT, lower balance scores were associated with abdominal distention/ascites (p = .009) and splenomegaly (p = .017). Lower pre-LT platelet count correlated with poorer balance (r = .532, p = .017) and lower strength and agility scores (r = .446, p = .043). Significant moderate inverse correlations were found between weight/body mass index z-scores and BOT-2 components. Post-LT children continue to demonstrate decreased levels of motor proficiency and functional capacity but report less fatigue and increased physical activity.

CONCLUSIONS

Older children and adolescents undergoing LT are at risk of decreased physical function, highlighting the need for pre- and post-LT rehabilitation to optimize long term outcomes.

A pilot feasibility study of an ultrasound-based tool to assess muscle mass in children with liver disease

BACKGROUND

Sarcopenia is associated with adverse outcomes following liver transplantation, and at-risk children must be identified and prehabilitated. The gold standard for assessing sarcopenia in end-stage liver disease (ESLD) is CT assessment of the total Psoas Muscle Area (tPMA). However, radiation exposure and sedation requirements make this approach impractical for children. The bilateral anterior thigh thickness (BATT) is the cumulative measurement of the rectus femoris and vastus intermedius muscles by ultrasound and has been used to identify sarcopenia in adults. There are no studies assessing muscle mass in children using ultrasound. We hypothesized that measuring BATT with ultrasound in children with ESLD is feasible and is associated with sarcopenia.

METHODS

A prospective pilot feasibility study of patients with ESLD on the liver transplantation waitlist and age-matched healthy controls. BATT was measured by a single operator using ultrasound. tPMA indices were determined by CT imaging, along with clinical and anthropometric data.

RESULTS

Thirty children were studied between September 2021 and December 2022, 15 listed patients aged 4-30 months, and 15 controls aged 4-32 months. No major technical challenges or complications were encountered while performing the ultrasounds. Median BATTs of 30.8 mm (interquartile range: 27.9-32.8 mm) versus 32.7 mm (interquartile range: 31.8-36.9 mm) were demonstrated in the ESLD and control groups, respectively, and p = 0.01. A positive correlation (R = 0.603) was demonstrated between BATT and tPMA at the L4-5 level among patients with ESLD. No correlation was observed between BATT and anthropometrics.

CONCLUSIONS

This study yields novel data on the feasibility of ultrasound to measure mid-thigh thickness in children with ESLD and suggests a correlation between BATT and tPMA, the gold standard for diagnosing sarcopenia. It sets the stage for ultrasound as a simple, noninvasive, and easily repeatable tool for assessing sarcopenia in children.

Effects of changes in skeletal muscle mass on the prognosis of pediatric malignant solid tumors

PURPOSE

This study aims to clarify the relationship between changes in skeletal muscle mass during treatment and prognosis of pediatric malignant solid tumors.

METHODS

Patients with pediatric malignant solid tumors who were treated at Kyushu University Hospital from 2007 to 2017 were divided into two groups: the progression-free survival (PFS) group and the relapse/death (R/D) group; the psoas major muscle volume (PMV) was then compared. We also measured the PMV and psoas muscle area (PMA) of pediatric patients with no complications who underwent surgery for acute appendicitis (control) and compared the values with those of patients with malignant tumors.

RESULTS

No significant differences were observed in the PMV and PMA between patients with appendicitis and those with malignant tumors. Significant differences were found in the rate of change in PMV between the PFS (1.424) and R/D groups (1.071) (P = 0.0024). When the cut-off value of the rate of change in the PMV was 1.20, patients whose rate of change in PMV was ≥ 1.20 had longer PFS (P = 0.0231) and overall survival (P = 0.0229) than those whose rate of change was < 1.20.

CONCLUSION

Pediatric patients with malignant solid tumors and increased skeletal muscle mass during treatment have a good prognosis.

Perspectives on Sarcopenia as a Predictor for Outcomes in Pediatric Patients with Chronic Liver Disease

Sarcopenia, a pathologic deficiency of muscle mass and function, has emerged as an important secondary feature of many chronic disease states. For adults with end stage liver disease, there are multiple mechanisms which contribute to sarcopenia and its presence has proven to be an important predictor of morbidity and mortality. In children, there are only a limited number of reports which investigate the role of sarcopenia in liver disease. These studies, which are discussed and summarized in this review, report small, single-center analyses with dissimilar study cohorts and varying clinical definitions. Still, children meeting the study entry criteria have sarcopenia with a reported prevalence of 24-70%. When assessed, sarcopenia appears to be associated with more severe disease but is independent of the Pediatric End-Stage Liver Disease (PELD) score and does not correlate with age, gender, or traditional anthropometric measures such as weight, height, weight-for-height, or body mass index (BMI). While individual studies may identify sarcopenia as a statistically significant risk factor for certain post-transplant outcomes such as longer ICU stay, longer duration of intubation, repeat operation, development of serious infection, longer hospital stay, death, or long-term growth failure, such associations are not consistently replicated across studies. Finally, although various methods of muscle mass quantification are utilized, the most reported is the total psoas muscle surface area (tPMSA) on computed tomography. This method, along with others such as skeletal muscle area and skeletal muscle index, have had normative values recently defined and these collective efforts should enable researchers a common basis of comparison when delineating sarcopenia, and its impact, across various study populations in future investigations - including in children with liver disease.

Muscle Strength, Agility, and Body Composition in Children With Intestinal Failure on Parenteral Nutrition

OBJECTIVES

With increasing number of children with intestinal failure (IF) on long-term parenteral nutrition (PN), this study assesses the impact of IF on muscle strength, speed, and agility and body composition (BC), identifying clinical factors that may predict impairment.

METHODS

Cross-sectional study in children 5-18 years with IF on PN. Assessments included Bruininks-Oseretsky Test of Motor Proficiency-2 strength and agility subtest (BOT-2), and grip strength. BC data from dual-energy x-ray absorptiometry (DXA) measurements and clinical variables were collected by chart abstraction. Data were compared to age and sex matched controls and population norms.

RESULTS

Twenty-one children with IF (14 males), median age 8.33 (IQR: 6.96-11.04) years and 33 controls (20 males), 8.25 (6.67-10.79) years were included. Strength and agility ( P &lt; 0.001) and grip strength ( P = 0.001) differed between groups. Nine of 21 (43%) of children with IF scored &gt;1 standard deviation (SD) below mean on BOT-2 and 13 of 21 (62%) had grip strength &gt;1 SD below mean. DXA measurements showed 10 of 18 (56%) of children had lower fat-free mass (FFM)% and higher fat mass (FM)% than reference norms. Decreased FFM% was associated with lower BOT-2 scores ( r = 0.479; P = 0.044) and grip strength scores &gt;1 SD below mean ( P = 0.047). Additional clinical factors significantly impacting strength and agility included prematurity, height, hospitalizations, sepsis, and small bowel length.

CONCLUSIONS

Children with IF are at risk of decreased muscle strength and agility, along with altered BC. Ongoing medical, nutritional, and rehabilitation intervention is vital to optimize outcomes.

Motor outcomes in young children pre-and one-year post-liver transplant

BACKGROUND

Motor skill acquisition plays an important role in physical activity participation and overall social and physical health. Limited studies have examined motor development in children pre-and post-liver transplant (LT).

METHODS

Retrospective review of motor outcomes in children <6 years old with cholestatic liver disease assessed pre-and 1-year post-isolated LT. Measures include Alberta Infant Motor Scale and Peabody Developmental Motor Scales (gross motor quotient (GMQ), fine motor quotient (FMQ), and total motor quotient (TMQ)). Association of medical variables with motor outcomes was explored.

RESULTS

Participants included 33 (58% male) children with diagnoses of biliary atresia (70%), Alagille syndrome (21%), and others (9%). Median age at LT was 10 (IQR 7.0-20.5) months. Pre-LT >75% of children were at risk for motor delay (≤10^th percentile on AIMS/ ≥1SD below mean GMQ). Post-LT, 52% scored ≥1 SD below the mean GMQ compared with 22% FMQ. Children at risk/delayed pre-LT had an increased risk of motor delay on GMQ post-LT (odds ratio 11.43, 95% CI 1.12-116.7, p = .017). Higher INR pre-LT correlated with lower TMQ post-LT (r = -.51, p = .003). Longer waitlist time correlated with lower FMQ post-LT (r = .41, p = .03). GMQ post-LT and height z-scores pre-LT (r = .46, p = .02) and post-LT (r = .45, p < .01) were positively correlated. There was no correlation with presence of ascites, weight z-score, length of hospitalization, and age at LT.

CONCLUSIONS

Young children have increased risk of motor delay pre-LT, which may persist post-LT. Severity of liver disease and growth delays may impact motor development, highlighting the need for ongoing rehabilitation pre- and post-LT.

Sarcopenia and Fat Mass in Children With Chronic Liver Disease and Its Impact on Liver Transplantation

In adults, weight loss and sarcopenia are prognostic indicators of poor outcomes for patients awaiting liver transplant (LT). We tested the hypothesis that sarcopenia in children awaiting LT was related to poor outcomes.

Methods

Children with end-stage chronic liver disease undergoing assessment for LT were recruited into an observational longitudinal study. Anthropometry and body composition (BC; whole-body dual-energy x-ray absorptiometry scan) were assessed before and, on average, 1 year after LT.

Results

Eleven children (6 females:5 males) were assessed (4.7 to 17.2 years; median, 9.9) at baseline. Nine children went on to have an LT. The aspartate aminotransferase-to-platelet ratio index had a significant positive correlation with trunk lean mass and trunk lean mass index (LMI) SD score (SDS). At baseline, 4 patients were sarcopenic with appendicular LMI SDS less than -1.96. All fat mass and fat mass index (FMI) SDSs were within the normal range (above -1.96). There was a strong negative correlation between FMI SDS and height SDS. After transplant, there was a significant reduction in trunk LMI from 1.20 to -0.51 (95% CI, 1.03-2.4; P < 0.01). Body mass index SDS had a negative correlation with days to discharge after transplant. The majority of patients discharged after 16 days were sarcopenic. One year after transplantation, all patients were alive with normal graft function regardless of BC before LT.

Conclusion

FMIs were normal regardless of LMIs and correlated negatively with height. BC was related to days to discharge after LT but not to outcomes a year after LT.

Sarcopenia in Children with Solid Organ Tumors: An Instrumental Era

Sarcopenia has recently been studied in both adults and children and was found to be a prognostic marker for adverse outcome in a variety of patient groups. Our research showed that sarcopenia is a relevant marker in predicting outcome in children with solid organ tumors, such as hepatoblastoma and neuroblastoma. This was especially true in very ill, high-risk groups. Children with cancer have a higher likelihood of ongoing loss of skeletal muscle mass due to a mismatch in energy intake and expenditure. Additionally, the effects of cancer therapy, hormonal alterations, chronic inflammation, multi-organ dysfunction, and a hypermetabolic state all contribute to a loss of skeletal muscle mass. Sarcopenia seems to be able to pinpoint this waste to a high degree in a new and objective way, making it an additional tool in predicting and improving outcome in children. This article focuses on the current state of sarcopenia in children with solid organ tumors. It details the pathophysiological mechanisms behind sarcopenia, highlighting the technical features of the available methods for measuring muscle mass, strength, and function, including artificial intelligence (AI)-based techniques. It also reviews the latest research on sarcopenia in children, focusing on children with solid organ tumors.

Impact of muscle mass on the prognosis of liver transplantation for infants with biliary atresia

BACKGROUND

Sarcopenia in adult cirrhotic patients is associated with increased morbidity and mortality whereas in children it is still being studied. Anthropometric variables in cirrhotic children are not reliable for assessing muscle mass as they may be altered by ascites, edema, and organomegaly. Measuring the area of the psoas showed good correlation with muscle mass in adults. We aimed to study in cirrhotic infants undergoing liver transplantation the association of the psoas area with liver transplant prognosis as well as with several analytical and anthropometric parameters used to evaluate nutritional status.

METHODS

Retrospective cohort of 29 infants with cirrhosis due to biliary atresia who underwent abdominal CT scan as a pre-transplant study. We measured the psoas muscle index (PMI) at L4-L5 since it best correlates with muscle mass in pediatric patients. As there are no validated cut-off points to define sarcopenia in children under one year of age, PMI was recorded as a continuous variable and correlated with different prognostic, clinical, and analytical variables. The SPSS 17.0 package was used for statistical analysis and a P < 0.05 was considered significant.

RESULTS

29 infants (10 boys, 19 girls) were studied. 62% were Caucasian and the rest were South American. The mean age at CT scan was 8.5 months (range 3-15 months). There was a negative correlation between PMI and days of admission prior to liver transplant, previous infections, and bone fractures. Among the analytical parameters, cholinesterase, albumin, and prealbumin correlated positively with PMI (P < 0.05). No relationship was observed with anthropometric parameters: weight, height, BMI, brachial perimeter, or bioimpedance. During surgery, patients with lower PMI had a greater need for plasma transfusion, and in the immediate postoperative period, there was a longer stay in intensive care, more days of mechanical ventilation, and more days of hospital admission (P < 0.05). On the contrary, no relationship was found with other complications: bleeding, re-interventions, biliary leaks, rejection, thrombosis, re-transplantation, or infections.

CONCLUSIONS

The decrease in muscle mass is associated with increased morbidity in infants with biliary atresia undergoing liver transplantation. Muscle mass in these patients cannot be adequately assessed with anthropometric measurements commonly used in the clinic.

Utility of Preoperative Computed Tomography-Based Body Metrics in Relation to Postoperative Complications in Pediatric Liver Transplantation Recipients

Computed tomography (CT)-derived body metrics such as skeletal muscle index (SMI), psoas muscle index (PMI), and subcutaneous fat area index (ScFI) are measurable components of sarcopenia, frailty, and nutrition. While these body metrics are advocated in adults for predicting postoperative outcomes after liver transplantation (LT), little is known about their value in pediatric populations. This study assessed the relation between preoperative CT-based body metrics and postoperative short-term outcomes in pediatric LT recipients. Patients aged 0-18 years who underwent a primary LT were retrospectively included (n = 101; median age 0.5 years; range 0.2-17.1). SMI, PMI, and ScFI were derived from preoperative axial CT slices. Postoperative outcomes and complications within 90 days were correlated with the CT-based body metrics. To classify postoperative infections, the Clavien-Dindo (CD) classification was used. Subgroup analyses were performed for age groups (<1, 1-10, and >10 years old). An optimal threshold for test performance was defined using Youden's J-statistic and receiver operating characteristic curve as appropriate. ScFI was significantly (P = 0.001) correlated with moderate to severe postoperative infections (CD grade 3-5) in children aged <1 year, with the optimal ScFI threshold being ≤27.1 cm² /m² (sensitivity 80.4% and specificity 77.8%). A weak negative correlation between SMI and the total duration of hospital stay (R = -0.3; P = 0.01) and intensive care unit (ICU) stay (R = -0.3; P = 0.01) was observed in children aged <1 year. No other associations between CT-based body metrics and postoperative outcomes were shown. In children aged <1 year with cirrhotic liver disease undergoing LT, preoperative CT-based body metrics were correlated with moderate to severe postoperative infections (ScFI) and with longer duration of hospital and ICU stay (SMI), and thus can be considered important tools for pre-LT risk assessment.

Psoas muscle area and paraspinal muscle fat in children and young adults with or without obesity and fatty liver

Background

Little is known about the muscle condition in children with obesity.

Objectives

To investigate the effect of obesity and fatty liver on muscle area and muscle fat in children and young adults.

Materials and methods

We evaluated consecutive liver fat quantification MRIs in children and young adults between June 2015 and April 2019. We obtained hepatic fat and paraspinal muscle fat at mid L2 from the fat map, psoas muscle area (PMA) at mid L3, and z-score of PMA. The patient’s age, height and weight at the time of the MRI were recorded. Body mass index (BMI) z-score was also calculated. Spearman correlation and partial correlation analyses were performed. Univariate and multivariate regression analyses were also performed using significant variables.

Results

A total of 132 patients (97 male) were included with a median age of 13.0 years (interquartile range 11–16 years). The median BMI was 23.7 kg/m² (interquartile range 21.2–27.7 kg/m²). The weight, BMI, liver fat, and z-score of PMA were all higher in male patients than they were in female patients. The amount of liver fat had no correlation with muscle fat or PMA z-score after adjusting BMI. However, the BMI z-score was positively correlated with the PMA z-score (ρ = 0.432, p<0.001) even after adjusting for liver fat. On regression analyses, the BMI z-score had linear positive relationship with PMA z-score (β = 0.289, p<0.001) and muscle fat (β = 0.218, p = 0.016).

Conclusions

Male children and young adults have greater PMA than do female children and young adults. Obesity is associated with higher PMA and paraspinal muscle fat. However, liver fat is not related with the muscle condition in children and young adults.

Muscle mass change during chemotherapy in children with high-risk neuroblastoma: a retrospective case series of 24 patients

The clinical characteristics, cause, and risk factors of sarcopenia are unclear in children. The aim of this study was to describe the course of and identify the factors related to muscle mass change during chemotherapy in children with neuroblastoma. A total of 24 consecutive patients aged below 18 years with newly diagnosed high-risk neuroblastoma between 2010 and 2018 in our hospital were enrolled in a case-series study. The psoas muscle index (PMI) was calculated as a parameter of muscle mass based on computer tomography (CT) images of the psoas muscle. PMIs were evaluated at 4 time points (TPs): TP1, at the diagnosis of neuroblastoma; TP2, after the first cycle of chemotherapy; TP3, after the third cycle of chemotherapy; and TP4, at the end of the induction chemotherapy. PMI recovery was defined as an increase in PMI between TP2 and TP4. The mean PMI decreased by 15% between TP1 and TP2 (TP1 7.09 ± 0.99 vs. TP2 6.01 ± 0.98, P < 0.001) and by 10% between TP1 and TP4 (TP1 7.09 vs. TP4 6.35, P = 0.004). PMI recovery between TP1 and TP2 was observed in 7 (29%) patients. The median age of patients with PMI recovery was significantly lower (2 vs. 4 years, P = 0.028), and the proportion of boys was significantly higher in patients with PMI recovery (100% vs. 41%, P = 0.017).Conclusion: This study demonstrated that prominent PMI reduction occurs during the early time of chemotherapy, and a younger age and male sex may be predictive factors for PMI recovery. What is Known: • Sarcopenia is a common disorder in elderly people. • Several causes and risk factors have been reported in adults. • Children with previous hematological malignancies have decreased physical activity. What is New: • Prominent muscle mass loss was observed early in children with high-risk neuroblastoma during chemotherapy. • Age and sex were found to be potentially associated with muscle mass recovery.

Malnutrition in Pediatric Chronic Cholestatic Disease: An Up-to-Date Overview

Despite recent advances, the causes of and effective therapies for pediatric chronic cholestatic diseases remain elusive, and many patients progress to liver failure and need liver transplantation. Malnutrition is a common complication in these patients and is a well-recognized, tremendous challenge for the clinician. We undertook a narrative review of both recent and relevant older literature, published during the last 20 years, for studies linking nutrition to pediatric chronic cholestasis. The collected data confirm that malnutrition and failure to thrive are associated with increased risks of morbidity and mortality, and they also affect the outcomes of liver transplantation, including long-term survival. Malnutrition in children with chronic liver disease is multifactorial and with multiple potential nutritional deficiencies. To improve life expectancy and the quality of life, patients require careful assessments and appropriate management of their nutritional statuses by multidisciplinary teams, which can identify and/or prevent specific deficiencies and initiate appropriate interventions. Solutions available for the clinical management of these children in general, as well as those directed to specific etiologies, are summarized. We particularly focus on fat-soluble vitamin deficiency and malnutrition due to fat malabsorption. Supplemental feeding, including medium-chain triglycerides, essential fatty acids, branched-chain amino acids, and the extra calories needed to overcome the consequences of anorexia and high energy requirements, is reviewed. Future studies should address the need for further improving commercially available and nutritionally complete infant milk formulae for the dietary management of this fragile category of patients. The aid of a specialist dietitian, educational training regarding nutritional guidelines for stakeholders, and improving family nutritional health literacy appear essential.

Low psoas muscle index as an unfavorable factor in children with end-stage liver disease undergoing liver transplantation

Sarcopenia is common in cirrhotic adults and associated with waitlist mortality and worse outcome after liver transplantation. Psoas muscle mass has been used to define sarcopenia. Therefore, we aimed to determine the association between psoas muscle mass and waitlist mortality as well as post-transplant outcome in children with end-stage liver disease. Medical records and abdominal imaging of pediatric liver transplant candidates during 2010-2019 were reviewed. A subset of images was measured by two radiologists to determine inter-rater reliability. Psoas muscle surface area was determined at intervertebral lumbar disk 3-4 (L3-4) and 4-5 (L4-5) levels. PMI was calculated by psoas muscle surface area divided by height squared. We included 105 children, most with biliary atresia (84%). Patients with waitlist mortality had lower PMI compared to the ones who survived to transplantation (PMI at L3-4 levels 352.8 ± 162.5 vs. 416.8 ± 136.2 mm² /m² and at L4-5 levels 497.3 ± 167.8 vs. 571.4 ± 163.4 mm² /m² , both p = .04), but not in the multivariate analyses. For transplanted patients (n = 75), a higher rate of re-operation (39% vs. 15%, p = .03) and longer hospital stay (53 vs. 45 days, p = .02) were found in patients with lower PMI. Lower PMI is associated with higher re-operation rate and longer hospital stay following transplantation, but not waitlist mortality. PMI may be taken into consideration with other biomarkers to predict post-transplant complications.

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.

Investigation of the prognostic value of psoas muscle area measurement in pediatric patients before liver transplantation: A single-center retrospective study

BACKGROUND

In this study, our aim is to investigate the prognostic value of psoas muscle area (PMA) evaluation before liver transplantation (LT) in pediatric patients.

METHODS

Two hundred seventy-six patients under 18 years of age who underwent LT between January 2012 and December 2019 were included in the study. The patients' demographic, laboratory, clinical, and imaging data were scanned retrospectively. PMA was measured at the L4/5 level using computed tomography images. To determine reproducibility, a different radiologist evaluated 30 randomly selected patients.

RESULTS

In patients with end-stage liver disease (ESLD), PMA was significantly lower than in patients with acute liver failure (P < .001). In patients with ESLD, a weakly significant correlation was found between PMA and 1-year survival after LT (r: .251, P = .030), hospitalization period (r: -.275, P = .039), and pediatric ESLD score (r: -.338, P < .001). Interobserver correlation was excellent (ICC: .941, 95% CI: .925, .971).

CONCLUSION

In children with ESLD, PMA evaluated before LT can be used as a negative prognostic factor.

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.

Sarcopenia is a prognostic outcome marker in children with high-risk hepatoblastoma

BACKGROUND

Children with hepatoblastoma (HB) are at risk of sarcopenia due to immobility, chemotherapy, and malnutrition. We hypothesized that children with HB have a low preoperative total psoas muscle area (tPMA), reflecting sarcopenia, which negatively impacts outcome.

PROCEDURE

Retrospective study of children (1-10 years) with hepatoblastoma treated at a large university children's hospital from 2009 to 2018. tPMA was measured as the sum of the right and left psoas muscle area (PMA) at intervertebral disc levels L3-4 and L4-5. z-Scores were calculated using age- and gender-specific reference values and were compared to anthropometric measurements, clinical variables, and outcomes. Sarcopenia was defined as a tPMA z-score below -2.

RESULTS

Thirty-three children were included. Mean tPMA z-score was -2.18 ± 1.08, and 52% were sarcopenic. A poor correlation between tPMA and weight was seen (r = 0.35; confidence interval [CI] 0.01, 0.62; P = .045), and most children had weights within the normal range (mean z-score -0.55 ± 1.39). All children categorized as high risk with relapse (n = 5/12) were sarcopenic before surgery. Relapse was significantly higher in the high-risk sarcopenic group compared to the nonsarcopenic group (P = .008). The change in tPMA z-score 1-4 months after surgery did not improve in patients with relapse, but did improve in 75% of children without relapse.

CONCLUSIONS

The majority of children with HB were sarcopenic prior to surgery. Especially in children with high-risk hepatoblastoma, sarcopenia is an additional risk factor for relapse. Large multicenter studies are needed to confirm these preliminary results.

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.

Body composition assessment after pediatric liver transplant

BACKGROUND

Pediatric liver transplantation generally restores metabolic function; yet after transplantation, some children remain malnourished, have increased adiposity, and develop obesity. Measurement of body composition in the assessment of nutrition status could reduce adverse consequences in children.

METHODS

Anthropometric measurements, multiple-frequency bioelectrical impedance analysis, air displacement plethysmography, and ultrasound measurements were conducted on children recruited from the liver transplant program at the University of Minnesota Masonic Children's Hospital. A cross-sectional study was conducted to describe the quality of weight gain in post-liver transplant children between the ages of 2 and 17 years using multiple assessment tools (air displacement plethysmography, multiple-frequency bioelectrical impedance analysis, and ultrasound) and to determine whether multiple-frequency bioelectrical impedance analysis and ultrasound accurately describe body composition and quality of weight gain.

RESULTS

Mean percent body fat by air displacement plethysmography and multiple-frequency bioelectrical impedance analysis was 18.4% (±3.3) and 19.0% (±3.9), respectively (P > .99). There were insufficient data to examine the relationship between summed muscle and adipose thickness measures by ultrasound and percent body fat determined by air displacement plethysmography or multiple-frequency bioelectrical impedance analysis.

CONCLUSION

Percent body fat, fat mass, and fat-free mass measures determined by air displacement plethysmography and multiple-frequency bioelectrical impedance analysis were not statistically different, which suggests the stand-on device used in this study could be a useful body composition assessment tool for the pediatric population.

Body Composition Post Pediatric Liver Transplant: Implications and Assessment

Liver disease has a negative influence on growth and development of children. Measurement of body composition as a component of nutrition status assessment in children before and after transplant would facilitate tailoring of nutrition therapy. A comprehensive literature search on pediatric liver transplant and body composition assessment was performed using a modified systematic approach. This review includes evidence specific to body composition of children undergoing liver transplant and a discussion of relevant body composition assessment methods for this population. Malnutrition is commonly seen in children with liver disease prior to transplant because of the disrupted metabolic pathways from liver dysfunction; however, malnutrition is not consistently diagnosed. Within 1 year of transplant, children tend to quickly recover with weight gain and linear growth. In some children, obesity and sarcopenia have been observed as long-term posttransplant outcomes. Body composition assessment tools have been utilized in diagnosing nutrition status in adults; yet there are limited studies that use these tools in the pediatric liver-transplant population. Technologies available to assess body composition include air displacement plethysmography, dual-energy x-ray absorptiometry, bioimpedance, and ultrasound. Total body potassium has been used for body composition assessment in adults and children post liver transplant; however, this method is not applicable in a clinical setting. We conclude that understanding posttransplant body composition could help clinicians diagnose and treat malnutrition.

Pediatric length-of-stay index following liver transplantation

BACKGROUND

PELD scores are used to reduce waitlist mortality, but they do not accurately predict likelihood of prolonged length-of-stay or higher costs associated with it. This study aims to create a pediatric length-of-stay (LOS) index to predict increased risk of prolonged stay following liver transplantation.

METHODS

The scoring system generated predicts length-of-stay following pediatric liver transplantation. With univariate and multivariate analyses on data from 5669 pediatric liver transplant recipients, independent recipient/donor risk factors for prolonged stay (>30 days) were identified. Multiple imputations accounted for missing variables.

RESULTS

The most significant factors were ICU admission (OR 2.92, CI 2.27-3.75), recipient bilirubin >32 (OR 2.35, CI 1.70-3.25), and hemodialysis 1 week before transplantation (OR 2.27, CI 1.57-3.27). The LOS index assigns weighted scoring points to factors to predict prolonged stay (C-statistic of .72). The index demonstrated discrimination across the population after dividing it into quartiles for prolonged stay.

CONCLUSIONS

The pediatric LOS index, utilizing 13 donor/recipient factors, can assess the risk for pediatric liver transplantation prolonged stay. Important predictive factors are hemodialysis, ICU admission, recipient weight and bilirubin, and recipient life support status.

The Use of Visceral Proteins as Nutrition Markers: An ASPEN Position Paper

Serum albumin and prealbumin, well-known visceral proteins, have traditionally been considered useful biochemical laboratory values in a nutrition assessment. However, recent literature disputes this contention. The aim of this document is to clarify that these proteins characterize inflammation rather than describe nutrition status or protein-energy malnutrition. Both critical illness and chronic illness are characterized by inflammation and, as such, hepatic reprioritization of protein synthesis occurs, resulting in lower serum concentrations of albumin and prealbumin. In addition, the redistribution of serum proteins occurs because of an increase in capillary permeability. There is an association between inflammation and malnutrition, however, not between malnutrition and visceral-protein levels. These proteins correlate well with patients' risk for adverse outcomes rather than with protein-energy malnutrition. Therefore, serum albumin and prealbumin should not serve as proxy measures of total body protein or total muscle mass and should not be used as nutrition markers. This paper has been approved by the American Society for Parenteral and Enteral Nutrition Board of Directors.

Physical Function, Physical Activity, and Quality of Life After Liver Transplantation

Robust physical activity after liver transplantation is an important determinant of longterm health, similar in its importance to the value of pretransplant activity for withstanding the immediate stress of transplantation. Although transplantation normally enables rapid recovery of liver synthetic and metabolic functions, the recovery of physical capacity and performance to normal levels is delayed and often incomplete. Anatomic measurements of sarcopenia and the physical performance indicators of frailty both tend to improve slowly, and they may, in fact, decrease further in the posttransplant period, especially when the common extrahepatic drivers of muscle loss, such as the elements of the metabolic syndrome, persist or intensify after transplantation. Posttransplant exercise improves fitness, which is a conclusion based on 2 observational studies and 3 randomized trials that assessed endpoints of strength testing, energy expenditure in metabolic equivalents, and peak or maximal oxygen uptake. Importantly, 1 controlled trial found that exercise also improved quality of life (QOL) measured by the Short Form 36 survey, consistent with multiple reports of the value of social support and engagement in sports activity for improving posttransplant QOL. Developing evidence-based standards for post-liver transplant physical activity baseline testing and sustainment of intensity and quality is a key unmet need in transplant hepatology. At present, it is reasonable for transplant teams to assess fitness and design a tailored exercise program when a recipient is first discharged, to record and reinforce progress at all posttransplant visits, and to set realistic longterm performance goals that will often achieve recommended standards for the healthy general population.

Deficits in Muscle Strength and Physical Performance Influence Physical Activity in Sarcopenic Children After Liver Transplantation

Sarcopenia is a muscle disease characterized by reduced skeletal muscle mass (SMM), muscle strength, and physical performance. Reduced SMM has been identified in children after liver transplantation (LT), but no information related to muscle strength/physical performance or lifestyle factors contributing to sarcopenia is available. We hypothesized that sarcopenia, as determined by measures of SMM, muscle strength, and physical performance, is highly prevalent in children after LT and is related to poor diet quality (DQ) and physical inactivity. A cross-sectional study in post-LT children (n = 22) and age-matched healthy controls (n = 47) between the ages of 6 and 18 years examining body composition (dual energy X-ray absorptiometry and multiple skinfold), measures of muscle strength (handgrip, sit-to-stand, and push-ups), physical performance (6-minute walk test and stair climb test), diet (3-day food intake), and physical activity (accelerometer) was conducted. Low muscle strength/physical performance and SMM (SMM z scores ≤-1.5) were defined by values 2 standard deviations below the mean values for age- and sex-matched controls. Sarcopenia occurred in 36% of children who underwent LT, and they had significantly lower scores for muscle strength (sit-to-stand and push-up tests) and physical performance (stair climb test) than controls (P < 0.05). Deficits in physical performance in children with sarcopenia were predominantly revealed by longer stair climbing times (P = 0.03), with no differences in other muscle tests. Low SMM, muscle strength, and physical performance were associated with a lower amount of time spent in fairly and very active physical activity, but no associations with DQ were found. Sarcopenia is highly prevalent in children after LT and is related to lower moderate-to-vigorous physical activity. Development of effective rehabilitation strategies to treat sarcopenia are needed in post-LT children.

A North American Expert Opinion Statement on Sarcopenia in Liver Transplantation

Loss of muscle mass and function, or sarcopenia, is a common feature of cirrhosis and contributes significantly to morbidity and mortality in this population. Sarcopenia is a main indicator of adverse outcomes in this population, including poor quality of life, hepatic decompensation, mortality in patients with cirrhosis evaluated for liver transplantation (LT), longer hospital and intensive care unit stay, higher incidence of infection following LT, and higher overall health care cost. Although it is clear that muscle mass is an important predictor of LT outcomes, many questions remain, including the best modality for assessing muscle mass, the optimal cut-off values for sarcopenia, the ideal timing and frequency of muscle mass assessment, and how to best incorporate the concept of sarcopenia into clinical decision making. For these reasons, we assembled a group of experts to form the North American Working Group on Sarcopenia in Liver Transplantation to use evidence from the medical literature to address these outstanding questions regarding sarcopenia in LT. We believe sarcopenia assessment should be considered in all patients with cirrhosis evaluated for liver transplantation. Skeletal muscle index (SMI) assessed by computed tomography constitutes the best-studied technique for assessing sarcopenia in patients with cirrhosis. Cut-off values for sarcopenia, defined as SMI < 50 cm² /m² in male and < 39 cm² /m² in female patients, constitute the validated definition for sarcopenia in patients with cirrhosis. Conclusion: The management of sarcopenia requires a multipronged approach including nutrition, exercise, and additional pharmacological therapy as deemed necessary. Future studies should evaluate whether recovery of sarcopenia with nutritional management in combination with an exercise program is sustainable as well as how improvement in muscle mass might be associated with improvement in clinical outcomes.

Sarcopenia in Chronic Liver Disease: Impact on Outcomes

Malnutrition is a common complication in patients with end-stage liver disease (ESLD) awaiting liver transplantation (LT). Malnutrition and sarcopenia overlap in etiology and outcomes, with sarcopenia being defined as reduced skeletal muscle mass and muscle function. The purpose of this review was to identify the prevalence of sarcopenia with and without obesity in adults and children with ESLD and to assess the methodological considerations in sarcopenia diagnosis and the association of sarcopenia with pre- and post-LT outcomes. A total of 38 articles (35 adult and 3 pediatric articles) retrieved from PubMed or Web of Science databases were included. In adults, the prevalence rates of pre-LT sarcopenia, pre-LT sarcopenic obesity (SO), post-LT sarcopenia, and post-LT SO were 14%-78%, 2%-42%, 30%-100%, and 88%, respectively. Only 2 adult studies assessed muscle function in patients diagnosed with sarcopenia. The presence of pre-LT sarcopenia is associated with higher wait-list mortality, greater postoperative mortality, higher infection risk and postoperative complications, longer intensive care unit (ICU) stay, and ventilator dependency. The emerging pediatric data suggest that sarcopenia is prevalent in pre- and post-LT periods. In 1 pediatric study, sarcopenia was associated with poor growth, longer perioperative length of stay (total/ICU) and ventilator dependency, and increased rehospitalization in children after LT. In conclusion, there is a high prevalence of sarcopenia in adults and children with ESLD. Sarcopenia is associated with adverse clinical outcomes. The present review is limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing sarcopenia. Future studies are needed to standardize the sarcopenia diagnosis and muscle function assessment, particularly in the pediatric population, to enable early identification and treatment of sarcopenia in adults and children with ESLD.

Low Muscle Mass as a Prognostic Factor for Early Postoperative Outcomes in Pediatric Patients Undergoing the Fontan Operation: A Retrospective Cohort Study

The impact of low muscle mass on pediatric cardiac patients remains unclear. We investigated the impact of low muscle mass on early postoperative outcomes in patients undergoing the Fontan operation. The electronic medical records of 74 patients (aged <18 years) who underwent the Fontan operation were retrospectively reviewed. The cross-sectional areas of the erector spinae and pectoralis muscles were measured using preoperative chest computed tomography (CT), normalized to the body surface area, and combined to obtain the total skeletal muscle index (TSMI). Low muscle mass was defined as a TSMI value lower than the median TSMI for the second quintile. The incidence of major postoperative complications was higher in patients with low muscle mass than in those with high muscle mass (48% (15/31) versus 14% (6/43); P = 0.003). Multivariable analyses revealed that a higher TSMI was associated with a lower likelihood of an increased duration of intensive care unit (>5 days) and hospital stay (>14 days) (odds ratio (OR) 0.86; 95% confidence interval (CI) 0.77–0.96; P = 0.006 and OR 0.92; 95% CI 0.85–0.99; P = 0.035 per 1 cm²/m² increase in TSMI) and incidence of major postoperative complications (OR 0.90; 95% CI 0.82–0.99; P = 0.039 per 1 cm²/m² increase in TSMI). Preoperative low muscle mass was associated with poor early postoperative outcomes in pediatric patients undergoing the Fontan operation.

Pediatric Sarcopenia: A Paradigm in the Overall Definition of Malnutrition in Children?

BACKGROUND

Malnutrition is a common complication in children with chronic diseases. Sarcopenia is one component of malnutrition, characterized by reduced skeletal muscle mass (SMM) and muscle function. The presence of sarcopenia is associated with adverse outcomes in children. Although there is growing research interest in sarcopenia, no review has been done on this novel concept in pediatrics. The purpose of this review was to explore current evidence in sarcopenia with and without obesity and to evaluate the knowledge gaps in the assessment of childhood sarcopenia.

METHODS

A total of 12 articles retrieved from PubMed or Web of Science databases were included.

RESULTS

Limited studies have elucidated sarcopenia in pediatrics. Challenges in sarcopenia assessment include heterogeneity in definition and absence of standardized body composition methods used to measure SMM and muscle function tests. There is a lack of age-specific and gender-specific normative data for SMM, particularly in young children and infants. None of the studies incorporated muscle function assessment, causing potential bias and misclassification of sarcopenia. The research in childhood sarcopenia is also hampered by low study quality, limited number of outcomes-based research, and lack of longitudinal data.

CONCLUSION

Consensus needs to be reached in methodological approaches in sarcopenia diagnosis, body composition measurements, and age-appropriate muscle function tests in pediatrics. Careful considerations on growth, neurocognitive status, and factors influencing development in various clinical populations are warranted. Early identification of sarcopenia is crucial to enable targeted treatment and prevention to be carried out across the pediatric clinical populations.

High Burden of Subclinical Cardiovascular Target Organ Damage After Pediatric Liver Transplantation

Cardiovascular (CV) events account for 8%-13% of deaths after liver transplantation (LT) in adulthood. Although CV risk factors (RFs) are present, little is known about the prevalence of subclinical CV target organ damage (TOD) in children after LT. The aim of this prospective observational study was to assess the prevalence of subclinical CV TOD in children after LT and to identify RFs contributing to CV damage as potential targets for clinical intervention. In this study, 104 children after LT (54% female, 46% male; aged 11.5 ± 3.8 years) underwent cross-sectional assessment of subclinical TOD by carotid-femoral pulse wave velocity (PWV), carotid intima-media thickness (IMT), and left ventricular mass index (LVMI). Results were correlated with the presence of CV RFs (obesity, hypertension, dyslipidemia, renal impairment, anemia, and microinflammation). Of the patients, 22% were exposed to 2 CV RFs, and 36% displayed 3 or more CV RFs. Pathological results for PWV, IMT, and LVMI were found in 21.9%, 57.0%, and 11.1% of patients, respectively. In the multivariate analysis, diastolic blood pressure (P = 0.01) and estimated glomerular filtration rate (eGFR; P = 0.03) were independently associated with PWV, eGFR (P = 0.005), and age at LT (P = 0.048) with IMT and body mass index with LVMI (P = 0.004). In conclusion, patients after pediatric LT carry a substantial burden of subclinical CV TOD. Identification of modifiable CV RFs opens opportunities for targeted intervention in order to reduce CV morbidity and mortality in the future.

Healthy Body Weights With Corticosteroid-free Immunosuppression Is the Best Predictor of Cardiovascular Health in Children After Liver Transplantation

INTRODUCTION

Cardiometabolic dysregulation (CMD) influences morbidity and mortality risk in adults post-liver transplantation (LTx). CMD is reported in 10% to 25% of pediatric LTx recipients, but no information regarding the longitudinal expression of CMD is available. The study objective was to examine the longitudinal expression of CMD and associations with body composition and growth in children post-LTx.

METHODS

A retrospective review was conducted in youth (34 F/30 M) who underwent LTx between 1994 and 2015 at the Stollery Children's Hospital. Primary outcomes included serum markers of CMD (insulin, glucose, hemoglobin A1C [A1C], homeostasis model assessment for insulin resistance [abnormal >3], lipid panel triglycerides, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol) and systolic/diastolic blood pressure (BP: absolute/z scores).

RESULTS

Mean (±SD) age, weight z, height z, body mass index z was 9.7 ± 3.4 years (3.5-17.9), 0.26 ± 1.03, 0.017 ± 1.2, and 0.41 ± 1.05, respectively. The majority of children had percentage fat mass, percentage fat-free mass within normal reference ranges. Systolic/diastolic BP was within healthy references ranges in 83.1% and 93.5% of children, respectively. Serum insulin (83.4%) and high-density lipoprotein-cholesterol (43.9%) concentrations were low, with abnormal findings of other laboratory markers found in <5% of participants. Abnormal findings for metabolic parameters were independent of weight z, body mass index z, fat mass, and corticosteroids but were positively related to child's age (>9.7 years) and fat-free mass (total, arms). Insulin levels decreased significantly in the first 4 years post-LTx, but no changes in lipid panel, A1C and glucose were noted over 10 years.

CONCLUSIONS

Pediatric LTx recipients with healthy body weights and corticosteroid-free immunosuppression have a low expression of CMD over 10 years.