Severe Sarcopenia and Increased Fat Stores in Pediatric Patients With Liver, Kidney, or Intestine Failure

Comparing body composition measures in children with end stage liver disease using noninvasive bioimpedance analysis

BACKGROUND

Chronic liver disease (CLD) in children, often leads to cirrhosis and end-stage liver disease (ESLD). CLD poses significant challenges in management and prognosis. Assessing body composition, including sarcopenia, is increasingly recognized as important in understanding outcomes in this population.

METHODS

We conducted a prospective observational study, involving children aged 2 to 18 years with ESLD awaiting liver transplantation. Socio-demographic, clinical, and laboratory data were collected, and body composition was assessed using Bioelectrical Impedance Analysis (BIA). Sarcopenia was defined using age-specific cut-off points for appendicular skeletal muscle mass (aSMM) and fat-free mass (FFM).

RESULTS

The study included 57 children (42.1% girls, 57.9% boys; median age: 10.9 years) with liver cirrhosis. Of them 11 (19.3%) died during the study. The mean duration of living with end-stage liver disease prior to participation was 5.43 years [IQR: 3.32, 8.39]. The most common etiology was biliary atresia (24.6%), followed by cryptogenic (22.8%). Deceased children exhibited significantly higher sarcopenia prevalence, lower basal metabolic rate and growth scores compared to survivors (P < 0.05), (771.0 vs. 934.0, P = 0.166) (65.0 vs. 80.5, P = 0.005). Total body and limb-specified lean mass were lower in deceased children, although not statistically significant. Similarly, total mineral (90% normal) and bone mineral content were lower in deceased children, with a significant difference observed only in water-to-FFM percentage (72.5 vs. 73.1, P = 0.009).

CONCLUSION

This study highlights the high prevalence of sarcopenia among children with ESLD and its association with adverse outcomes, including mortality. Bioimpedance analysis emerges as a promising, non-invasive method for assessing body composition in pediatric ESLD, warranting further investigation and integration into clinical practice.

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.

Renal impairment is prevalent in pediatric NAFLD/MASLD and associated with disease severity

OBJECTIVES

Renal impairment is prevalent in adults with nonalcoholic fatty liver disease (NAFLD/metabolic dysfunction associated steatotic liver disease [MASLD]) and is associated with increased mortality. Pediatric data are limited. Our objective was to determine the prevalence of hyperfiltration or chronic kidney disease (CKD) in children with NAFLD/MASLD and determine links with liver disease severity.

METHODS

Data from children who had previously participated in prospective, multicenter, pediatric studies by the Nonalcoholic Steatohepatitis Clinical Research Network (NASH-CRN) were collected. Renal function was determined using the calculated glomerular filtration rate (cGFR). Hyperfiltration was defined as cGFR > 135 mL/min/1.73m2, while CKD stage 2 or higher as cGFR < 90 mL/min/1.73 m2. Renal dysfunction progression was defined as transition from normal to hyperfiltration or to CKD stage ≥ 2, or change in CKD by ≥1 stage. Multinomial logistic regression models were used to determine the prevalence of CKD and independent associations between CKD and liver disease severity.

RESULTS

The study included 1164 children (age 13 ± 3 years, 72% male, 71% Hispanic). The median cGFR was 121 mL/min/1.73 m2; 12% had CKD stage 2-5, while 27% had hyperfiltration. Hyperfiltration was independently associated with significant liver fibrosis (odds ratio: 1.45). Baseline renal function was not associated with progression in liver disease over a 2-year period (n = 145). Renal dysfunction worsened in 19% independently of other clinical risk factors. Progression of renal impairment was not associated with change in liver disease severity.

CONCLUSIONS

Renal impairment is prevalent in children with NAFLD/MASLD and hyperfiltration is independently associated with significant liver fibrosis. Almost 1/5 children have evidence of progression in renal dysfunction over 2 years, not associated with change in liver disease severity. Future assessments including additional renal impairment biomarkers are needed.

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.

Skeletal Muscle Mass Assessment in Pediatric Patients: Development of a Normative Equation and Assessment of Factors Associated With a Low Skeletal Muscle Mass in PICU Patients

OBJECTIVES

To develop an equation for defining a low skeletal muscle mass (SMM) in children and to investigate risk factors and outcomes associated with low SMM in critically ill pediatric patients.

DESIGN

Single-center retrospective pediatric cohorts, 2011-2018.

SETTING

Tertiary Emergency and Critical Care Center of Kyushu University Hospital in Japan.

PATIENTS

We studied two cohorts of pediatric patients 1-15 years old who underwent abdominal CT at the level of the third lumbar vertebra (L3). First a cohort of trauma patients presented to the emergency department in whom we developed an SMM regression equation. Second, a cohort of patients who had undergone abdominal CT within 3 days of PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The equation for estimating normal SMM used sex, age, and weight. Low SMM was defined as less than 80% of normal. In the 112 patients in the PICU cohort, median (range) age was 68 (13-191) months, and 83 (74.1%) had underlying disease. There was low SMM in 54 patients (48.2%). Regarding associations, using odds ratio (OR) and 95% CI, we found that low dietary intake (OR 4.33 [95% CI, 1.37-13.70]; p = 0.013) and the presence of underlying disease (OR 7.44 [95% CI, 2.10-26.30]; p = 0.002) were independently associated with greater odds of low SMM. Low SMM, compared with normal SMM, was also associated with longer hospital stays (42.5 d vs. 20.5 d; p = 0.007; β, 1.59; 95% CI, 1.09-2.33; p = 0.016).

CONCLUSIONS

In this retrospective PICU cohort from a single center in Japan, we found that low SMM at PICU admission was present in almost half the cases. Low SMM, as defined by being less than 80% of the normal, was associated with greater odds of low dietary intake and underlying chronic disease. Furthermore, low SMM was associated with longer hospital stays.

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.

Preoperative low muscle mass and early postoperative outcomes in children undergoing living donor liver transplantation: A retrospective study

Low skeletal muscle mass may develop in children with end-stage liver disease, affecting postoperative outcomes. We retrospectively investigated whether preoperative low muscle mass was associated with early postoperative outcomes in pediatric patients undergoing living donor liver transplantation (LDLT). Electronic medical records of children (age below 12 y) who underwent LDLT between February 1, 2007, and January 31, 2018, were reviewed. The cross-sectional areas of psoas, quadratus lumborum, and erector spinae muscles at the level of fourth-fifth lumbar intervertebral disks were measured using abdominal CT images, divided by the square of the height and were added to obtain the total skeletal muscle index (TSMI). The patients were divided into two groups according to the median TSMI in the second quintile (1859.1 mm 2 /m 2 ). Complications in the early postoperative period (within 30 d after surgery) classified as Clavien-Dindo grade 3 or higher were considered major complications. Logistic regression analyses were performed to determine the association between preoperative low muscle mass and early postoperative outcomes. In the study population of 123 patients (median age, 14 mo; range, 8-38 mo) who underwent LDLT, 29% and 71% were classified in the low (mean TSMI, 1642.5 ± 187.0 mm 2 /m 2 ) and high (mean TSMI 2188.1 ± 273.5 mm 2 /m 2 ) muscle mass groups, respectively. The rates of major complications, mechanical ventilation >96 hours, intensive care unit stay >14 days, hospital stay >30 days, and in-hospital mortality were not significantly different between the 2 groups. Additionally, adverse outcomes according to pediatric end-stage liver disease scores and sex were not significantly different between the 2 groups. In conclusion, preoperative low muscle mass defined by TSMI was not associated with early postoperative outcomes in pediatric patients undergoing LDLT.

Challenges and physiological implications of sarcopenia in children and youth in health and disease

PURPOSE OF REVIEW

Highlight the controversies and challenges associated with a sarcopenia diagnosis in infants and children and the potential physiological mechanisms contributing to this disorder.

RECENT FINDINGS

Sarcopenia has been recently identified in infants and children with chronic diseases such as liver, cardiac, gastrointestinal, cancer and organ transplant recipients. However, there is no consensus regarding the definition of pediatric sarcopenia. Different sarcopenic phenotypes (sarcopenia and sarcopenic obesity) have been identified in healthy children and children with chronic disease. Both conditions have been associated with adverse clinical outcomes (e.g. delayed growth, increased hospitalization) in children and youth with chronic disease. The etiology of pediatric sarcopenia is likely multifactorial associated with malnutrition, physical inactivity and altered metabolic environments influencing skeletal muscle mass accumulation and function. Gaps in the literature include the lack of standard tools that should be used for the evaluation of skeletal muscular fitness and body composition in sarcopenia, particularly in infants and young children (<4years).

SUMMARY

Longitudinal evaluation of sarcopenia expression and the underlying physiological and lifestyle factors contributing to pediatric sarcopenia are important to understand to ensure effective rehabilitation strategies can be developed and to avoid the adverse clinical consequences in children.

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.

Sarcopenia is associated with osteopenia and impaired quality of life in children with genetic intrahepatic cholestatic liver disease

BACKGROUND

Sarcopenia occurs in pediatric chronic liver disease, although the prevalence and contributing factors in genetic intrahepatic cholestasis are not well-described. The objective of this study was to measure muscle mass in school-aged children with genetic intrahepatic cholestasis and assess relationships between sarcopenia, clinical variables, and outcomes.

METHODS

Estimated skeletal muscle mass (eSMM) was calculated on dual-energy x-ray absorptiometry obtained in a Childhood Liver Disease Research Network study of children with bile acid synthesis disorders(BASD) alpha-1 antitrypsin deficiency (a1ATd), chronic intrahepatic cholestasis (CIC), and Alagille syndrome (ALGS). Relationships between eSMM, liver disease, and transplant-free survival were assessed.

RESULTS

eSMM was calculated in 127 participants (5-18 y): 12 BASD, 41 a1ATd, 33 CIC, and 41 ALGS. eSMM z-score was lower in CIC (-1.6 ± 1.3) and ALGS (-2.1 ± 1.0) than BASD (-0.1 ± 1.1) and a1ATd (-0.5 ± 0.8, p < 0.001). Sarcopenia (defined as eSMM z-score ≤- 2) was present in 33.3% of CIC and 41.5% of ALGS participants. eSMM correlated with bone mineral density in the 4 disease groups (r=0.52-0.55, p < 0.001-0.07), but not serum bile acids, bilirubin, aspartate aminotransferase/platelet ratio index, or clinically evident portal hypertension. Of the 2 patients who died (1 with sarcopenia) and 18 who underwent liver transplant (LT, 4 with sarcopenia), eSMM z-score did not predict transplant-free survival. eSMM z-score correlated with the Physical Pediatric Quality of Life Inventory score (r=0.38-0.53, p = 0.007-0.04) in CIC and a1ATd.

CONCLUSION

Severe sarcopenia occurs in some children with ALGS and CIC. The lack of correlation between eSMM and biochemical cholestasis suggests mechanisms beyond cholestasis contribute to sarcopenia. While sarcopenia did not predict transplant-free survival, LT and death were infrequent events. Future studies may define mechanisms of sarcopenia in genetic intrahepatic cholestasis.

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.

Sarcopenia in youth

Recent research has revealed causes other than aging that may induce sarcopenia in young people, contrary to the long-studied age-dependent reduction in muscular mass and function. The risk of sarcopenia begins in early adulthood, resulting in exaggerated muscle dysfunction in later life. Despite its clinical significance, research on youth-onset sarcopenia is still in its infancy. Due to a paucity of epidemiologic data and standardized criteria for sarcopenia in youth, determining the prevalence of sarcopenia in the young population remains challenging. Based on the evidence, >1 in every 10 young adults of most ethnicities is estimated to have sarcopenia. This review summarizes the possible etiologies of sarcopenia in young populations, including metabolic syndrome, physical inactivity, inadequate nutrition, inherent and perinatal factors, vitamin D deficiency, endocrinopathy, an imbalance of gut microbiota, neuromuscular diseases, organ failure, malignancy, and other inflammatory disorders. This is the first review of the current knowledge on the importance, prevalence, diagnosis, and causes of sarcopenia in youth.

Habitual physical activity in patients born with oesophageal atresia: a multicenter cross-sectional study and comparison to a healthy reference cohort matched for gender and age

Oesophageal atresia (EA) is associated with life-long gastrointestinal and respiratory morbidity and other associated malformations. The aim of this study is to compare physical activity (PA) levels of children and adolescents with and without EA. A validated questionnaire (MoMo-PAQ) was used to evaluate PA in EA patients EA (4-17 years), who were randomly matched for gender and age (1:5) with a representative sample of the Motorik-Modul Longitudinal Study (n = 6233). Sports activity per week (sports index) and minutes of moderate to vigorous physical activity per week (MVPA minutes) were calculated. Correlations between PA and medical factors were analysed. In total, 104 patients and 520 controls were included. Children with EA were significantly less active at higher intensities (mean MPVA minutes 462; 95% confidence interval (CI): 370-554) compared to controls (626; 95% CI: 576-676), although there was no statistically significant difference in the sports index (187; 95% CI: 156-220 versus 220; 95% CI: 203-237). A lower mean weight-for-age and height-for-age, additional urogenital (r =  - 0.20, p = 0.04) or anorectal malformation (r =  - 0.24, p = 0.01) were associated with fewer MVPA minutes. For other medical factors (prematurity, type of repair, congenital heart disease, skeletal malformation or symptom load), no statistically significant association with PA was found.  Conclusion: EA patients participated in PA at a similar level but lower intensities compared to the reference cohort. PA in EA patients was largely independent of medical factors.

TRIAL REGISTRATION

German Clinical Trials Register (ID: DRKS00025276) on September 6, 2021.

WHAT IS KNOWN

• Oesophageal atresia is associated with a low body weight and height, delayed development of motor skills and impaired lung function and exercise capacity.

WHAT IS NEW

• Patients with oesophageal atresia have a similar amount of sports activity per week but engage significantly less in moderate to vigorous physical activities compared to peers. • Physical activity was  associated with weight-for-age and height-for-age, but largely independent of symptom load and other medical factors.

Establishment and validation of reference values for abdominal skeletal muscle compartments in children

BACKGROUND & AIMS

Sarcopenia, resulting from skeletal muscle loss, is a serious concern in children, for whom nutrition and physical activity are essential for growth. In sarcopenia research, the skeletal muscle mass is often obtained from computed tomography (CT) cross-sectional images in both adults and children; however, the method of evaluating skeletal muscle using CT, especially the area range to be measured, has not yet been validated in children. The aim of this study is to establish reference values for three compartments of the abdominal skeletal muscle area (aSMA) obtained from cross-sectional CT images, and to validate the differences among them by assessing correlations with physical development.

METHODS

We conducted a single-centre, retrospective, cross-sectional study and included patients aged 1-17 years who underwent abdominal CT at Chiba University Hospital from 2007 to 2020. Patients with chronic diseases such as malignant tumours and inflammatory bowel disease were excluded from the analysis. aSMA was obtained from CT cross-sections at the lumbar L3-L4 intervertebral disc level by dividing it into three compartments: the psoas muscle area (PMA), paraspinal muscle area (PSMA), and total skeletal muscle area (TSMA). Quartile regression curves by sex and muscle compartment were generated using non-crossover and nonparametric regression quantile estimation. The correlation between each compartment of aSMA with height and weight was assessed using Spearman's rank correlation coefficient.

RESULTS

We analysed the abdominal CT images of 593 children (male: n = 335, female: n = 258) and generated curves predictive for the 5th, 25th, 50th, 75th, and 95th percentiles for each compartment of aSMA by sex. In patients aged 13 years and older, boys had significantly larger aSMA areas than girls in all three compartments. Among the three compartments, PSMA had the strongest correlation coefficient with height and weight for both boys and girls.

CONCLUSIONS

We generated quantile regression curves for three aSMA compartments obtained from cross-sectional CT images and established reference values in children. PSMA values were most strongly correlated with height and weight among the three aSMA compartments.

Prediction of whole body composition utilizing cross-sectional abdominal imaging in pediatrics

BACKGROUND

Although body composition is an important determinant of pediatric health outcomes, we lack tools to routinely assess it in clinical practice. We define models to predict whole-body skeletal muscle and fat composition, as measured by dual X-ray absorptiometry (DXA) or whole-body magnetic resonance imaging (MRI), in pediatric oncology and healthy pediatric cohorts, respectively.

METHODS

Pediatric oncology patients (≥5 to ≤18 years) undergoing an abdominal CT were prospectively recruited for a concurrent study DXA scan. Cross-sectional areas of skeletal muscle and total adipose tissue at each lumbar vertebral level (L1-L5) were quantified and optimal linear regression models were defined. Whole body and cross-sectional MRI data from a previously recruited cohort of healthy children (≥5 to ≤18 years) was analyzed separately.

RESULTS

Eighty pediatric oncology patients (57% male; age range 5.1-18.4 y) were included. Cross-sectional areas of skeletal muscle and total adipose tissue at lumbar vertebral levels (L1-L5) were correlated with whole-body lean soft tissue mass (LSTM) (R²= 0.896-0.940) and fat mass (FM) (R²= 0.874-0.936) (p < 0.001). Linear regression models were improved by the addition of height for prediction of LSTM (adjusted R² = 0.946-0^.971; p < 0.001) and by the addition of height and sex (adjusted R² = 0.930-0.953) (p < 0^.001)) for prediction of whole body FM. High correlation between lumbar cross-sectional tissue areas and whole-body volumes of skeletal muscle and fat, as measured by whole-body MRI, was confirmed in an independent cohort of 73 healthy children.

CONCLUSION

Regression models can predict whole-body skeletal muscle and fat in pediatric patients utilizing cross-sectional abdominal images.

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.

Reference values for MRI-derived psoas and paraspinal muscles and macroscopic fat infiltrations in paraspinal muscles in children

BACKGROUND

Sarcopenia, defined as loss of skeletal muscle mass, is a novel term associated with adverse outcomes in children. Magnetic Resonance Imaging (MRI) is a safe and precise technique for measuring tissue compartments and is commonly used in most routine paediatric imaging protocols. Currently, there is a lack of MRI-derived normative data which can help in determining the level of sarcopenia. This study aimed to introduce reference values of total psoas muscle area (tPMA), total paraspinal muscle area (tPSMA), and total macroscopic fat infiltrations of the PSMA (tMFI).

METHODS

In this retrospective study, the local database was searched for abdominal and pelvic region MRI studies of children aged from 1 to 18 years (mean age (standard deviation (SD)) of 9.8 (5.5) years) performed in the years 2010-2021. Children with chronic diseases and a history of surgical interventions were excluded from the analysis. Finally, a total of 465 healthy children (n = 233 girls, n = 232 boys) were enrolled in the study. The values of the tPMA, tPMSA, and tMFI were measured in square centimetres (cm² ) at the level of the L4/L5 intervertebral disc as the sum of the left and right regions. Age-specific and sex-specific muscle, fat, and body mass index percentile charts were constructed using the LMS method. Inter-observer agreement and intra-observer reproducibility were assessed using the Bland-Altman plots.

RESULTS

Both tPMA and tPSMA showed continuous increases in size (in cm² ) throughout all age groups. At the age of 18, the median tPMA areas reached 26.37 cm² in girls and 40.43 cm² in boys. Corresponding tPSMA values were higher, reaching the level of 40.76 cm² in girls and 56.66 cm² in boys. The mean value of tMFI within the paraspinal muscles was 5.0% (SD 3.65%) of their total area in girls and 3.5% (SD 2.25%) in boys with the actual difference between sexes up to 0.96 cm² . Excellent intra-observer reproducibility and inter-observer agreement were noted. Actual mean differences for tPMA were at the level of 0.43 and 0.39 cm² , respectively. Mean bias for tPSMA was 0.1 cm² for inter-observer and 0.05 cm² for intra-observer measurements.

CONCLUSIONS

Our findings demonstrate novel and highly reproducible sex-specific MRI-derived reference values of tPMS, tPSMA, and tMFI at the level of the L4/L5 intervertebral disc for children from 1 to 18 years old, which may guide a clinician in the assessment of sarcopenia, a prognostic outcome marker in children.

Defining Normal Ranges of Skeletal Muscle Area and Skeletal Muscle Index in Children on CT Using an Automated Deep Learning Pipeline: Implications for Sarcopenia Diagnosis

BACKGROUND. Skeletal muscle area (SMA), representing skeletal muscle cross-sectional area at the L3 vertebral level, and skeletal muscle index (SMI), representing height-normalized SMA, can serve as markers of sarcopenia. Normal SMA and SMI values have been reported primarily in adults. OBJECTIVE. The purpose of this study was to use an automated deep learning (DL) pipeline for muscle segmentation on abdominal CT to define normative age- and sex-based values for pediatric muscle cross-sectional area as a guide for diagnosis of sarcopenia in children. METHODS. This retrospective study reviewed records of patients who underwent abdominal CT at Cincinnati Children's Hospital Medical Center from January 1, 2009, to January 3, 2019. Patients were excluded on the basis of age outside of the eligible range (2.00-18.99 years), body mass index (BMI) outside of 5-95% age-based percentiles using CDC and WHO growth charts, known medical condition, medication use, support devices, surgery, or missing axial images at the L3 level. A previously validated automated DL pipeline was used to identify an axial slice at L3 and segment skeletal muscle to generate SMA and SMI. Pearson correlation coefficients were computed. Quantile regression analysis was used to plot SMA and SMI as functions of age and sex and to determine age- and sex-based percentile values. RESULTS. Of 8817 patients who underwent abdominal CT during the study period, 2168 (mean age, 12.3 ± 4.3 [SD] years; 1125 female patients, 1043 male patients) met inclusion criteria. Mean BMI-for-age percentile based on CDC and WHO growth charts was 64.8% ± 25.3% for female patients and 61.4% ± 25.8% for male patients. SMA showed strong correlation with weight, height, age, and BMI for male (0.79-0.94) and female (0.75-0.90) patients; SMI showed weak-to-moderate correlation with weight, height, age, and BMI for male (0.25-0.57) and female (0-0.43) patients. Normal SMA and SMI ranges for age and sex were expressed as curves and as a lookup table, identifying 54 male and 59 female patients with muscle measurements below the 5th percentile regression curve. CONCLUSION. By using an automated DL pipeline in a large sample of carefully selected children, normal ranges for SMA and SMI were calculated as functions of age and sex. CLINICAL IMPACT. The normative values should aid the diagnosis of sarcopenia in children.

Sarcopenic Obesity in Children and Adolescents: A Systematic Review

Sarcopenic obesity (SO) is defined as co-occurrence of increased fat mass and sarcopenia and may predict adverse health outcomes in the pediatric population. However, the prevalence of SO and its association with adverse health outcomes have not been well defined in children and adolescents. We systematically reviewed data on the SO definition, prevalence, and adverse outcomes in the pediatric population. A total of 18 articles retrieved from PubMed or Web of Science databases were included. Overall, there was a wide heterogeneity in the methods and thresholds used to define SO. The prevalence of SO ranged from 5.66% to 69.7% in girls, with a range between 7.2% and 81.3% in boys. Of the 8 studies that evaluated outcomes related to SO, all showed a significant association of SO with cardiometabolic outcomes, non-alcoholic fatty liver disease (NAFLD) severity, inflammation, and mental health. In conclusion, this review found that SO is highly prevalent in children and adolescents and is associated with various adverse health outcomes. Findings of this review highlight the need for the development of a consensus regarding definition, standardized evaluation methods, and age and gender thresholds for SO for different ethnicities in the pediatric population. Further studies are needed to understand the relationship between obesity and sarcopenia and SO impact on adverse health outcomes in children and adolescents.

Sarcopenia prevalence in pediatric intestinal transplant recipients: Implications on post-transplant outcomes

BACKGROUND

Sarcopenia has been associated with poor surgical outcomes but has not been studied in pediatric intestinal transplantation. We aimed to determine sarcopenia prevalence in intestinal transplant recipients and the association of sarcopenia with outcomes.

METHODS

We performed a cross-sectional retrospective chart review of intestinal transplant recipients from 2000-present. We estimated total psoas muscle area (tPMA) at L3-L4 and L4-L5 from computed tomography scans prior to or in the immediate peri-operative period. Sarcopenia was defined by tPMA below the 5^th percentile for age and sex. We built a Cox-proportional hazards model to determine the association between sarcopenia and patient and graft survival.

RESULTS

Of the 56 intestinal transplant recipients included, 36 (64%) were sarcopenic. Graft survival was 79% at one year and 59% at five years. Overall patient survival was 86% at one year and 76% at five years. Peri-transplant sarcopenia was associated with improved graft survival (Hazard ratio 0.42, 95% confidence interval: 0.20-0.88) but not overall survival (Hazard ratio 0.47, 95% confidence interval: 0.19-1.20).

CONCLUSIONS

In this first report of sarcopenia in pediatric intestinal transplant, we found a high sarcopenia prevalence without an association with worse outcomes. The potential improved graft survival in sarcopenic patients along with underlying mechanisms warrant further exploration.

Prognostic impact of sarcopenia in children with cancer: a focus on the psoas muscle area (PMA) imaging in the clinical practice

Skeletal muscle plays a crucial part in the metabolic and inflammatory response. "Sarcopenia", defined as a pathological condition of reduced strength, quantity and quality of skeletal muscle mass, may often develop in the young age as the secondary consequence of a systemic inflammatory illness, like cancer. In children with cancer, sarcopenia is a common finding, playing a negative role in their prognosis. However, its prevalence in clinical practice is underestimated. Moreover, several pre- and post-natal factors may influence skeletal muscle development in childhood, making the issue more complex. Given the frequent use of radiological imaging in clinical practice, prompt analysis of body composition is feasible and able to detect the presence of reduced fat-free mass (FFM) among pediatric patients with cancer. We discuss the recent advances in the study of body composition in children with cancer, dissecting the role of the psoas muscle area (PMA) measure, obtained from computerized tomography (CT) or magnetic resonance images (MRI) as a marker of sarcopenia in this setting. Since age and sex-specific percentile curves for PMA and a PMA z-scores calculator are available online, such a tool may be useful to simply detect and treat sarcopenia and its consequences in childhood cancer.

Automated segmentation of whole-body CT images for body composition analysis in pediatric patients using a deep neural network

OBJECTIVES

To develop an automatic segmentation algorithm using a deep neural network with transfer learning applicable to whole-body PET-CT images in children.

METHODS

For model development, we utilized transfer learning with a pre-trained model based on adult patients. We used CT images of 31 pediatric patients under 19 years of age (mean age, 9.6 years) who underwent PET-CT from institution #1 for transfer learning. Two radiologists manually labeled the skin, bone, muscle, abdominal visceral fat, subcutaneous fat, internal organs, and central nervous system in each CT slice and used these as references. For external validation, we collected 14 pediatric PET/CT scans from institution #2 (mean age, 9.1 years). The Dice similarity coefficients (DSCs), sensitivities, and precision were compared between the algorithms before and after transfer learning. In addition, we evaluated segmentation performance according to sex, age (≤ 8 vs. > 8 years), and body mass index (BMI, ≤ 20 vs. > 20 kg/m²).

RESULTS

The algorithm after transfer learning showed better performance than the algorithm before transfer learning for all body compositions (p < 0.001). The average DSC, sensitivity, and precision of each algorithm before and after transfer learning were 98.23% and 99.28%, 98.16% and 99.28%, and 98.29% and 99.28%, respectively. The segmentation performance of the algorithm was generally not affected by age, sex, or BMI, except for precision in the body muscle compartment.

CONCLUSION

The developed model with transfer learning enabled accurate and fully automated segmentation of multiple tissues on whole-body CT scans in children.

KEY POINTS

• We utilized transfer learning with a pre-trained segmentation algorithm for adult to develop an algorithm for automated segmentation of pediatric whole-body CT. • This algorithm showed excellent performance and was not affected by sex, age, or body mass index, except for precision in body muscle.

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.

Muscle-to-Fat Ratio for Predicting Metabolic Syndrome Components in Children with Overweight and Obesity

Background: Pediatric obesity has been linked to the components of metabolic syndrome (MetS: abdominal obesity, atherogenic dyslipidemia, elevated blood pressure, and insulin resistance). Data on the role of muscle mass in the development of MetS are sparse. We explored the interaction between the muscle-to-fat ratio (MFR) and MetS components in children with overweight or obesity. Methods: An observational study of 210 pediatric subjects (88 boys, mean age [±standard deviation (SD)] 11.9 ± 3.1 years, BMI z-score range 1.036-3.140) from January 2018 to January 2021. Body composition was measured by bioelectrical impedance analysis (Tanita MC-780 MA and GMON Professional Software), and MFR z-scores were calculated. Results: The 148 subjects (70%) who had MetS components were older (p = 0.008), had lower socioeconomic positions, higher triglyceride/high-density lipoprotein-cholesterol ratios, fat percentages (FATP), truncal FATPs (TRFATPs), and lower MFR z-scores (p < 0.001 for all parameters) than those without MetS components. The correlation between the MFR z-score and the BMI z-score was stronger in subjects with obesity than in subjects with overweight (r = -0.556 vs. r = -0.440, p < 0.001 for both). The risk for MetS components increased by 1.4 for every 3% increase in FATP or TRFATP [odds ratio (OR) = 1.4, confidence interval ([CI] 1.20, 1.64), p < 0.001]. The risk for MetS components was tripled for every 1 SD decrease in MFR z-scores [OR = 3.3, CI (1.74, 6.27), p < 0.001]. Conclusions: Given the strong predictive value of the MFR z-score in the development of early-onset MetS components, preventive strategies should apply interventions for improving the body composition parameters of both adiposity and muscle.

Body composition measured by bioelectrical impedance analysis is a viable alternative to magnetic resonance imaging in children with nonalcoholic fatty liver disease

OBJECTIVE

To determine the relationship between bioelectrical impedance analysis (BIA) and magnetic resonance imaging (MRI) obtained measures of body composition in children with nonalcoholic fatty liver disease (NAFLD).

METHODS

Youth with obesity and NAFLD who had BIA and abdominal MRI testing were included. BIA measured skeletal muscle mass (SMM), appendicular lean mass (ALM), trunk muscle mass (TMM), and percent body fat. MRI measured total psoas muscle surface area (tPMSA) and fat compartments. Univariate analysis described the relationship between BIA- and MRI-derived measurements. Multivariable regression analyses built a model with body composition measured via MRI.

RESULTS

115 patients (82 (71%) male, 38 (33%) Hispanic, median age14 years) were included. There was a strong correlation between tPMSA and SMM, ALM, and TMM (correlation coefficients [CCs]: 0.701, 0.689, 0.708, respectively; all P < .001). Higher SMM, ALM, and TMM were associated with higher tPMSA. This association remained after controlling for age, sex, ethnicity, type 2 diabetes mellitus status, and body mass index z-score. Total fat mass by BIA and MRI-determined total, subcutaneous, and intraperitoneal fat area correlated significantly (CCs: 0.813, 0.808, 0.515, respectively; all P < .001). In univariate regression, higher total fat mass by BIA was associated with increased total fat area and increased fat in each of the four regions measured by MRI. After controlling for confounders, the association between total fat mass by BIA and total fat area by MRI persisted.

CONCLUSIONS

BIA measures of muscle and fat mass correlate strongly with MRI measures of tPMSA and fat areas in children with obesity and NAFLD.

Sarcopenia in children with chronic liver disease: Prevalence and impact on liver transplant outcomes

Sarcopenia is a clinical condition characterized by a reduction in muscle mass, which typically affects adult patients; however, it has recently been recognized in pediatric literature. Few studies in children with chronic liver disease (CLD) undergoing liver transplantation (LT) have investigated the role of sarcopenia, with controversial results. The aim of our study was to assess the prevalence and impact of sarcopenia among children with CLD who are candidates for LT. We conducted a retrospective, single-center study at Bambino Gesù Children's Hospital (Rome, Italy) from July 2016 to July 2021, evaluating all children (0-16 years old) with CLD listed for LT with an abdomen computed tomography imaging available before LT. The total psoas muscle surface area (t-PMSA) was defined as the sum of left and right psoas muscle surface area measured at L4-L5 on axial images. The t-PMSA z-score was calculated according to reference data, and sarcopenia was defined as a t-PMSA z-score of ≤-2 (1-16 years) or a psoas muscle index [PMI; PMI = t-PMSA/(100 × BSA)] of <50th percentile of the population examined (<1 year). Clinical, laboratory, and LT outcome data were collected from all the patients with CLD. 27 out 48 (56%) of the patients aged 1-16 years were sarcopenic. No differences were noted in anthropometrics, nutritional support, liver function tests, model for ESLD (MELD), or pediatric ESLD (PELD) scores between patients with and without sarcopenia. The former showed a higher prevalence of respiratory complications (66.7% vs. 42.1%) and need for inotropes (40.7% vs. 10.8%) after LT. Among patients aged 0-1 years (n: 36), those with reduced muscle mass (50%) had a longer hospitalization time (44 vs. 24 days) and higher incidences of multi-organ failure syndrome (38.9% vs. 0%) and intensive care unit-related infections (61.1% vs. 27.8%) compared to those with greater muscle mass. t-PMSA and PMI were statistically significant predictors of LT outcomes. Sarcopenia is a reliable index of frailty in children with CLD, as its presence is associated with the risk of a more challenging LT. Future studies will have to investigate the functional aspects of sarcopenia and conceive preventive measures of muscle wasting in CLD patients.

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.

Total Psoas Muscle Area as a Marker for Sarcopenia Is Related to Outcome in Children With Neuroblastoma

Background: Sarcopenia describes a generalized loss of skeletal muscle mass, strength, or function. Determined by measuring the total psoas muscle area (tPMA) on cross-sectional imaging, sarcopenia is an independent marker for poor post-surgical outcomes in adults and children. Children with cancer are at high risk for sarcopenia due to immobility, chemotherapy, and cachexia. We hypothesize that sarcopenic children with neuroblastoma are at higher risk for poor post-operative outcomes. Patients and Methods: Retrospective analysis of children with neuroblastoma ages 1-15 years who were treated at our hospital from 2008 to 2016 with follow-up through March 2021. Psoas muscle area (PMA) was measured from cross-sectional images, using computed tomography (CT) and magnetic resonance imaging (MRI) scans at lumbar disc levels L3-4 and L4-5. tPMA is the sum of the left and right PMA. Z-scores were calculated using age- and gender-specific reference values. Sarcopenia was defined as a tPMA z-score below -2. A correlation of tPMA z-scores and sarcopenia with clinical variables and outcome was performed. Results: One hundred and sixty-four children with workup for neuroblastoma were identified, and 101 children fulfilled inclusion criteria for further analysis, with a mean age of 3.92 years (SD 2.71 years). Mean tPMA z-score at L4-5 was -2.37 (SD 1.02). Correlation of tPMA z-score at L4-5 with weight-for-age z-score was moderate (r = 0.54; 95% CI, 0.38, 0.66). No association between sarcopenia and short-term outcome was observed. Sarcopenia had a sensitivity of 0.82 (95% CI, 0.62-0.93) and a specificity of 0.48 (95% CI 0.36-0.61) in predicting 5-year survival. In a multiple regression analysis, pre-operative sarcopenia, pre-operative chemotherapy in the NB2004 high-risk group, unfavorable tumor histology, and age at diagnosis were associated with 5-year survival after surgery, with hazard ratios of 4.18 (95% CI 1.01-17.26), 2.46 (95% CI 1.02-5.92), 2.39 (95% CI 1.03-5.54), and 1.01 (95% CI 1.00-1.03), respectively. Conclusion: In this study, the majority of children had low tPMA z-scores and sarcopenia was a risk factor for decreased 5-year survival in children with neuroblastoma. Therefore, we suggest measuring the tPMA from pre-surgical cross-sectional imaging as a biomarker for additional risk stratification in children with neuroblastoma.

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.

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.

METABOLIC AND NUTRITIONAL REPERCUSSIONS OF LIVER DISEASE ON CHILDREN: HOW TO MINIMIZE THEM?

Objective:

To describe the metabolic and nutritional repercussions of chronic liver disease (CLD), proposing strategies that optimize nutritional therapy in the pre- and post-liver transplantation (LT) period, in order to promote favorable clinical outcomes and adequate growth and development, respectively.

Data sources:

Bibliographic search in the PubMed, Lilacs and SciELO databases of the last 12 years, in English and Portuguese; target population: children from early childhood to adolescence; keywords in Portuguese and their correlates in English: “Liver Transplant,” “Biliary Atresia,” “Nutrition Therapy,” “Nutritional Status,” and “Child”; in addition to Boolean logics “and” and “or,” and the manual search of articles.

Data synthesis:

Malnutrition in children with CLD is a very common condition and an important risk factor for morbidity and mortality. There is an increase in energy and protein demand, as well as difficulties in the absorption of carbohydrates, lipids and micronutrients such as fat-soluble vitamins and some minerals. An increase in the supply of energy, carbohydrates and proteins and micronutrients, especially fat-soluble vitamins, iron, zinc and calcium, is suggested, except in cases of hepatic encephalopathy (this restriction is indicated for a short period).

Conclusions:

Based on metabolic changes and anthropometric and body composition monitoring, a treatment plan should be developed, following the nutritional recommendations available, in order to minimize the negative impact of malnutrition on clinical outcomes during and after LT.

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.

Automated Segmentation of Abdominal Skeletal Muscle on Pediatric CT Scans Using Deep Learning

PURPOSE

To automate skeletal muscle segmentation in a pediatric population using convolutional neural networks that identify and segment the L3 level at CT.

MATERIALS AND METHODS

In this retrospective study, two sets of U-Net-based models were developed to identify the L3 level in the sagittal plane and segment the skeletal muscle from the corresponding axial image. For model development, 370 patients (sampled uniformly across age group from 0 to 18 years and including both sexes) were selected between January 2009 and January 2019, and ground truth L3 location and skeletal muscle segmentation were manually defined. Twenty percent (74 of 370) of the examinations were reserved for testing the L3 locator and muscle segmentation, while the remaining were used for training. For the L3 locator models, maximum intensity projections (MIPs) from a fixed number of central sections of sagittal reformats (either 12 or 18 sections) were used as input with or without transfer learning using an L3 localizer trained on an external dataset (four models total). For the skeletal muscle segmentation models, two loss functions (weighted Dice similarity coefficient [DSC] and binary cross-entropy) were used on models trained with or without data augmentation (four models total). Outputs from each model were compared with ground truth, and the mean relative error and DSC from each of the models were compared with one another.

RESULTS

L3 section detection trained with an 18-section MIP model with transfer learning had a mean error of 3.23 mm ± 2.61 standard deviation, which was within the reconstructed image thickness (3 or 5 mm). Skeletal muscle segmentation trained with the weighted DSC loss model without data augmentation had a mean DSC of 0.93 ± 0.03 and mean relative error of 0.04 ± 0.04.

CONCLUSION

Convolutional neural network models accurately identified the L3 level and segmented the skeletal muscle on pediatric CT scans.Supplemental material is available for this article.See also the commentary by Cadrin-Chênevert in this issue.© RSNA, 2021.

Establishing Reference Values for Lean Muscle Mass in the Pediatric Patient

OBJECTIVES

Adults with decreased muscle mass experience worse outcomes and more frequent complications. The effects of sarcopenia on pediatric outcomes are unknown. Our objective was to define reference values for lean muscle mass in a healthy pediatric population to facilitate future studies on the impact of lean muscle mass on pediatric outcomes.

PATIENTS AND METHODS

Bilateral psoas muscle surface area was measured by computed tomography in a healthy pediatric population undergoing evaluation after trauma. Pearson correlation coefficients (PCCs) were calculated for age, weight, height, body mass index (BMI), total psoas muscle area, and psoas muscle index (PMI; defined as psoas muscle area divided by height squared). Quantile regression was used to determine age- and sex-specific percentiles of psoas muscle area and PMI.

RESULTS

Analysis of 494 male and 288 female patients with available imaging (median age: 9.3 years, interquartile range: 5.4-13.4; 63.1% male) was performed. For males, age correlated strongly with total psoas volume (PCC = 0.87), height (0.95), and weight (0.88) and poorly with BMI (0.45). In females, age correlated strongly with total psoas volume (0.88), height (0.92), weight (0.88) and poorly with BMI (0.19). Gender-specific curves and charts were created using output from the quantile regression from reference values of the total psoas muscle area corresponding to the 25th, 50th, and 75th percentiles across all ages.

CONCLUSIONS

We created gender-specific reference charts for total and height-normalized psoas muscle area in healthy children based on age. These results can be used in future studies to establish the effects of sarcopenia in pediatric patients.

Short bowel syndrome in infancy: recent advances and practical management

Short bowel syndrome (SBS) is a rare condition characterised by extensive loss of intestinal mass secondary to congenital or acquired disease. The outcomes are determined by dependency on parenteral nutrition (PN), its possible complications and factors that influence intestinal adaptation. In order to achieve the best results, patients should be managed by a specialised multidisciplinary team with the aims of promoting growth and development, stimulating intestinal adaptation and preventing possible complications. This involves timely surgical management aimed at rescuing maximum bowel length and eventually re-establishing intestinal continuity where appropriate. A combination of enteral and parenteral nutrition needs to be targeted towards maintaining a balance between fulfilling the nutritional and metabolic needs of the child while preventing or at least minimising potential complications. Enteral nutrition and establishment of oral feeding play a fundamental role in stimulating bowel adaptation and promoting enteral autonomy. Other measures to promote enteral autonomy include the chyme recycling in patients where bowel is not in continuity, autologous gastrointestinal reconstruction and pharmacological treatments, including promising new therapies like teduglutide. Strategies such as lipid reduction, changing the type of lipid emulsion and cycling PN are associated with a reduction in the rates of intestinal failure-associated liver disease. Even though vast improvements have been made in the surgical and medical management of SBS, there is still lack of consensus in many aspects and collaboration is essential.

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.

Body Composition of Infants With Biliary Atresia: Anthropometric Measurements and Computed Tomography-based Body Metrics

OBJECTIVES

Biliary atresia (BA) causes neonatal cholestasis that requires hepatoportoenterostomy or liver transplantation (LT) for long-term survival. Nutritional optimization is necessary as sarcopenia and sarcopenic obesity have been associated with adverse clinical outcome. Currently, mid upper arm circumference (MUAC) is considered the most accurate indicator. The aim of the study was to determine computed tomography (CT)-based body metrics in infants with BA and to evaluate its correlation with MUAC.

METHODS

We retrospectively analyzed all BA infants below 2 years of age who underwent CT as part of LT screening at our hospital between 2006 and 2019. Measured variables were indexed with length and included: MUAC, total psoas muscle surface area (tPMSA), cross-sectional skeletal muscle area (CSMA), and total abdominal fat area. Intraclass correlation coefficients and Pearson coefficients were calculated. CSMA-to-abdominal fat area ratio was divided in quartiles, the lowest quartile group was considered sarcopenic obese.

RESULTS

Eighty infants with a median age of 4.6 months at LT screening were included. Intraclass correlation coefficients were: tPMSA = 0.94, CSMA = 0.92, and total abdominal fat area = 0.99. Correlation between MUAC z-score and indices of tPMSA, CSMA, and total abdominal fat area were r = 0.02, r = 0.06, and r = 0.43, respectively. The cut-off for sarcopenic obesity was CSMA-to-abdominal fat area ratio below 0.93.

CONCLUSIONS

In BA infants, it is possible to determine CT-based body metrics during LT screening with very strong interobserver agreement. Poor correlation between CT-based body metrics and MUAC suggests that CT-based body metrics provide additional information on body composition in BA infants, such as relative muscle mass.

Tracheostomy Post Liver Transplant: Predictors, Complications, and Outcomes

Background

Liver transplant (LT) patients have an increased risk of postoperative respiratory failure requiring tracheostomy. This study sought to characterize objective clinical predictors of tracheostomy.

Material/Methods

The records for 2017 LT patients at a single institution were reviewed. Patients requiring tracheostomy were first compared with all other patients. A case-control subgroup analysis was conducted in which 98 tracheostomy patients were matched with 98 non-tracheostomy LT patients. For the case-control study, muscle mass was assessed using preoperative computed tomography scans.

Results

Among 2017 LT patients, 98 required tracheostomy (5%), with a 19% complication rate. Tracheostomy patients were older and had a higher model for end-stage liver disease score, a lower body mass index (BMI), and a greater smoking history. Tracheostomy patients had a longer hospital stay (45 vs. 10 days, P<0.001) and worse 1-year survival (65% vs. 91%, P<0.001). Ten-year Cox regression patient survival for tracheostomy patients was significantly worse (32% vs. 68%, P<0.001). In the case-control analysis, respiratory failure patients were older (P<0.01) and had a lower BMI (P=0.05). They also had a muscle mass deficit of −39% compared with matched LT controls (P<0.001). No significant differences were seen with pre-LT total protein or albumin or with forced expiratory volume in 1 s divided by forced vital capacity (FEV1/FVC) values.

Conclusions

Predictors for respiratory failure requiring post-LT tracheostomy include higher model for end-stage liver disease score, older age, lower BMI, greater smoking history, and worse sarcopenia. Patients requiring tracheostomy have dramatically longer hospital stays and worse survival.

Muscle Mass Is Linked to Liver Disease Severity in Pediatric Nonalcoholic Fatty Liver Disease

OBJECTIVE

To investigate the association between muscle mass and liver disease severity in pediatric patients with non-alcoholic fatty liver disease (NAFLD).

STUDY DESIGN

This was a retrospective study of patients aged <20 years followed from 2009 to 2018. Muscle mass was estimated in all patients by measuring magnetic resonance imaging-based total psoas muscle surface area (tPMSA) and correcting for height (tPMSA index = tPMSA/height2). Two cohorts were studied, one with histological confirmation of NAFLD (n = 100) and the other with magnetic resonance imaging (MRI) evidence of hepatic steatosis (n = 236). Histology was scored using Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) criteria. MRI-measured proton density fat fraction (PDFF) and liver stiffness were collected. Demographic, clinical, and socioeconomic status (using a validated Community Deprivation Index [CDI]) were assessed as covariates. Univariate regression analyses, followed by multivariable regression analyses, were used to determine the relationships between tPMSA index and NAS, MRI-PDFF, and liver stiffness, adjusting for clinical, demographic, and CDI variables.

RESULTS

In the multivariable regression analyses, higher steatosis score was associated with a lower tPMSA index (OR, 0.73; 95% CI, 0.56-0.96) and younger age (OR, 0.84; 95% CI, 0.73-0.97). Liver PDFF was also significantly associated with the tPMSA index (P = .029), sex (P = .019), and CDI (P = .005). In contrast, liver stiffness was not associated with tPMSA in multivariable analyses.

CONCLUSIONS

tPMSA index was independently associated with both imaging and histological features of hepatic steatosis severity in children. Future studies should directly explore the presence and directionality of causative links between muscle mass and steatosis, as well as whether interventions that enhance muscle mass can reduce disease severity in children with NAFLD.

Sarcopenia in children and adolescents with chronic liver disease

OBJECTIVE

To investigate the occurrence of sarcopenia in children and adolescents with chronic liver disease.

METHODS

A series of cases, with patients aged 6-19 years of both genders, who were treated in Liver Outpatient Clinics. Weight, height, muscle strength (assessed by manual grip strength), and muscle mass (estimated through dual-energy X-ray absorptiometry) were measured. Sarcopenia was diagnosed based on the simultaneous presence of muscle mass and muscle strength déficits, defined as the values below the mean for muscle mass and strength of the studied population, according to gender. A descriptive analysis (mean and standard deviation) was performed, and the difference of means was calculated by Student's t-test.

RESULTS

A total of 85 patients were studied, mostly females (64.7%), with a mean age of 11.7 (SD=3.4) years. Sarcopenia was identified in 40% of the patients. Muscle strength déficit was found in 54.1% of the subjects, and 50.6% showed muscle mass déficit. The mean muscle mass for males was higher than that for females (6.07; SD=1.22kg/m²vs. 5.42; SD=1.10kg/m²; p=0.016). However, there was no significant difference in sex-related muscle strength (male=0.85; SD=0.52kgf/kgm² and female=0.68; SD=0.30kgf/kgm²; p=0.113).

CONCLUSION

The research findings identified that sarcopenia is a condition found in pediatric patients treated at a public referral institution for chronic liver disease.