Paediatric reference values for total psoas muscle area

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.

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.

Relationship among low baseline muscle mass, skeletal muscle quality, and mortality in critically ill children

BACKGROUND

Studies in adults have shown that low baseline muscle mass at intensive care unit (ICU) admission was associated with poor clinical outcomes. However, no information on the relationship between baseline muscle quality or mass and clinical outcomes in critically ill children was found.

METHODS

3775 children were admitted to the pediatric ICU (PICU), 262 were eligible for inclusion. Abdominal computed tomography was performed to assess baseline skeletal muscle mass and quality. Patients were categorized to normal or low group based on the cutoff value for predicting hospital mortality of the skeletal muscle index (SMI; 30.96 cm2/m2) and skeletal muscle density (SMD; 41.21 Hounsfield units).

RESULTS

Body mass index (BMI) (18.07 ± 4.44 vs 15.99 ± 4.51) and BMI-for-age z score (0.46 [-0.66 to 1.74] vs -0.87 [-1.69 to 0.05]) were greater in the normal-SMI group, the length of PICU stay was longer in the low-SMI group (16.00 days [8.50-32.50] vs 13.00 days [7.50-20.00]), and the in-PICU mortality rate in the normal-SMI group (10.00%) was lower than the low-SMI group (22.6%). Children with low SMD had a higher in-PICU mortality rate (25.6% vs 7.7%), were younger (36.00 months [12.00-120.00] vs 84.00 months [47.50-147.50]) and weighed less (16.40 kg [10.93-37.25] vs 23.00 kg [16.00-45.00]). Mortality was greater in patients with lower SMD and prolonged hospital stay (log-rank, P = 0.007). SMD was an independent predictor for length of PICU stay and in-PICU mortality.

CONCLUSIONS

Low baseline skeletal muscle quality in critically ill children is closely tied with a higher in-PICU mortality and longer PICU stay and is an independent risk factor for unfavorable clinical outcomes.

Reference Values for Paravertebral Muscle Size and Myosteatosis in Chinese Adults, a Nationwide Multicenter Study

RATIONALE AND OBJECTIVES

The paravertebral muscles, characterized by their susceptibility to severe size loss and fat infiltration in old age, lack established reference values for age-related variations in muscle parameters. This study aims to fill this gap by establishing reference values for paravertebral muscles in a Chinese adult population.

MATERIALS AND METHODS

This cross-sectional study utilized the baseline data from the prospective cohort China Action on Spine and Hip (CASH). A total of 4305 community-dwelling participants aged 21-80 years in China were recruited between 2013 and 2017. Pregnant women, individuals with metal implants, limited mobility or diseases/conditions (spinal tumor, infection, etc.) affecting lumbar vertebra were excluded from the study. Psoas and paraspinal muscles were measured in quantitative computed tomography (QCT) images at the L3 and L5 levels using Osirix software. Age-related reference values for muscle area, density, and fat fraction were constructed as percentile charts using the lambda-mu-sigma (LMS) method.

RESULTS

The paravertebral muscles exhibited an age-related decline in muscle area and density, coupled with an increase in muscle fat fraction. Between the ages of 25 and 75, the reductions in psoas and paraspinal muscle cross-sectional area at the L3 level were - 0.47%/yr and - 0.53%/yr in men, and - 0.19%/yr and - 0.23%/yr in women, respectively. Notably, accelerated muscle loss was observed during menopause and postmenopause in women (45-75 years) and intermittently during middle and old age in men (35-55 and 60-75 years). Besides, the age-related decreases in PSMA, PMA, and PSMD and the increases in PSMFF were more pronounced in L5 than in L3 CONCLUSION: This study shows distinct patterns of accelerated muscle loss were identified in menopausal and postmenopausal women and in middle-aged and old men. The findings contribute valuable information for future investigations on paravertebral muscle loss and myosteatosis.

Malnutrition, sarcopenia, and frailty assessment in pediatric transplantation

Nutrition assessment can be challenging in children with end-stage organ disease and in those requiring an organ transplant. The effect of poor nutrition status can exert long-lasting effects on children with end-stage organ disease requiring transplantation. Malnutrition, sarcopenia, and frailty are conditions that require provision of optimal nutrition to prevent or support the treatment of these conditions. Unfortunately, the literature on the assessment of malnutrition, sarcopenia, and frailty in pediatric end-stage organ disease is scarce, thus leading to confusion on how to effectively identify them. Recently, the addition of a variety of validated nutrition and functional assessment techniques has assisted with appropriate assessment of these conditions. The objective of this narrative review is to provide an overview of the current literature for pediatric assessment of malnutrition, sarcopenia, and frailty in the setting of solid organ transplantation and provide practicing nutrition clinicians a solid foundation for learning how to effectively assess these conditions with the current literature available.

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.

Sarcopenia in long-term survivors of cancer in childhood and adolescence: A cross-sectional study of calf muscle mass by peripheral quantitative computed tomography with an examination of the muscle-bone unit

BACKGROUND

Sarcopenia, a loss of systemic skeletal muscle mass (SMM), is prevalent in childhood cancer survivors and often accompanied by increased fat mass (sarcopenic obesity [SO]). We examined whether calf muscle cross-sectional area (CSA), measured by peripheral quantitative computed tomography (pQCT), can identify sarcopenia and SO in long-term survivors of pediatric acute lymphoblastic leukemia (ALL), and explored its relationship with adjacent bone geometry.

PROCEDURES

Calf muscle CSA and CSA Z scores at the 38% tibia in 70 subjects (median survival 15 years) were compared between sexes and ALL risk group, and their association with sarcopenia and SO evaluated. Relationships between bone strength and muscle mass were assessed further using linear regression and methods described by Schoenau et al. for evaluation of a functional muscle-bone unit.

RESULTS

A calf muscle CSA Z score of less than or equal to zero is 73.81% sensitive and 84.62% specific for detecting sarcopenia defined by height-adjusted appendicular lean mass measured by dual-energy x-ray absorptiometry. No significant difference in CSA Z scores was noted between sexes or ALL risk groups; however, Z scores were markedly higher in those without SO (adjusted odds ratio 0.529, 95% confidence interval [CI]: 0.340-0.824). Ratios of calf muscle mass to height and total bone mineral content at the 38% tibia are "sufficient" and consistent with estimated reference ranges for a healthy population.

CONCLUSIONS

CSA Z scores may represent a useful clinical measure of SMM and are predictive of SO in this population. Our results are supportive of a functional muscle-bone unit in long-term survivors of pediatric ALL.

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.

Establishment of a quantitative assessment model and web-based calculation tool for the skeletal muscle index in children

BACKGROUND & AIMS

The skeletal muscle index (SMI) is widely used in adults. The reference values for SMI in children are inadequate and require validation in pediatric patients for clinical usefulness. Therefore, this study developed a quantitative assessment model for SMI in children using standard deviation (SD) curves and validated the model's utility and generalizability.

METHODS

We examined three compartments of the abdominal skeletal muscle region. SMI was calculated as skeletal muscle area divided by height squared for each compartment (PMI, psoas muscle index; PSMI, paraspinal muscle index; TSMI, total skeletal muscle index). The optimal model was generated using random grouping methods (training and testing), polynomial regression analysis, and the mean squared error evaluation methods. The generated model was validated with previously published SMI data and clinical data of patients with inflammatory bowel disease.

RESULTS

The data of 474 children were analyzed. The previously reported SMI reference values overlapped well with our model. In patients with inflammatory bowel disease, the mean (SD) Z-scores for SMI were low in boys (PMI, -1.15 [1.11]; PSMI, -1.31 [1.07]; TSMI, -0.84 [0.91]) and girls (PMI, -1.22 [1.08]; PSMI, -1.44 [1.19]; TSMI, -0.74 [1.16]). Furthermore, SMI was positively correlated with body weight, body mass index, and serum albumin level, a nutritional marker, and negatively correlated with erythrocyte sedimentation rate, an inflammatory marker.

CONCLUSION

We established a quantitative assessment model for SMI and validated the model's generalizability and clinical usefulness. We generated an easy-to-use calculation tool for Z-scores from skeletal muscle area obtained from computed tomography images, age, and height information; it has been made publicly available (http://square.umin.ac.jp/ped-muscle-calc/index.html).

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 as a Prognostic Factor in Patients with Hepatoblastoma: Does It Influence Surgical Outcomes and Survival? Preliminary Retrospective Study

AIM

Sarcopenia is associated with poor prognosis in adult oncologic patients, with little evidence of this association in pediatric population, including hepatoblastoma.

METHODS

Retrospective study in patients with hepatoblastoma, divided into those with or without sarcopenia. Sarcopenia was assessed by measuring psoas muscle area (PMA) at L4-L5 level on the CT/MR and defined as z-score values ≤ 2. Relapse and mortality were analyzed.

RESULTS

Twenty-one patients (57.1% male) were included, with median age 35.7 months (IQR: 23.5-58.5). Seven (33.3%) had sarcopenia on initial studies compared to 14 (66.7%) who did not. No differences were found between groups in age, weight, PRETEXT, surgical treatment or. α-fetoprotein levels. Sarcopenia was associated with a higher rate of metastases at diagnosis (49.2% vs 0.0%; p = 0.026) and surgical complications (57.1% vs 21.4%, p = 0.047). After a median follow-up of 65.1 months (1.7-144.8), 2 patients (28.6%) had tumor relapse in sarcopenic group compared to 1 (7.1%) in non-sarcopenic group. Two patients died in sarcopenic group and 1 in non-sarcopenic group. Median event-free survival (EFS) was lower in sarcopenic group (100.38 ± 25.63 vs 118.91 ± 11.52 months) as well as overall survival (OS) (101.72 ± 24.86 vs 121.78 ± 8.75 months) with no statistical significance. Five-year EFS was also lower in sarcopenic group (71% vs 93%) as well as 5-year OS (71% vs 87%).

CONCLUSIONS

Sarcopenia at diagnosis was associated with a higher rate of metastases and surgical complications in hepatoblastoma. Our data shows the first evidence of its role as a possible poor prognostic factor, influencing survival and risk of relapse.

LEVEL OF EVIDENCE

II.

TYPE OF STUDY

Original article. Retrospective study.

Body composition in pediatric patients

Undernutrition is highly prevalent in children who are critically ill and is associated with increased morbidity and mortality, including a higher risk of infection due to transitory immunological disorders, inadequate wound healing, reduced gut function, longer dependency on mechanical ventilation, and longer hospital stays compared with eutrophic children who are critically ill. Nutrition care studies have proposed that early interventions targeting nutrition assessment can prevent or minimize the complications of undernutrition. Stress promotes an acute inflammatory response mediated by cytokines, resulting in increased basal metabolism and nitrogen excretion and leading to muscle loss and changes in body composition. Therefore, the inclusion of body composition assessment is important in the evaluation of these patients because, in addition to the nutrition aspect, body composition seems to predict clinical prognosis. Several techniques can be used to assess body composition, such as arm measurements, calf circumference, grip strength, bioelectrical impedance analysis, and imaging examinations, including computed tomography and dual-energy x-ray absorptiometry. This review of available evidence suggests that arm measurements seem to be well-established in assessing body composition in children who are critically ill, and that bioelectrical impedance analysis with phase angle, handgrip strength, calf circumference and ultrasound seem to be promising in this evaluation. However, further robust studies based on scientific evidence are necessary.

Sarcopenia in Children With Wilms Tumor: A Marker of Undernutrition Which May Impact Adversely on Clinical Outcomes

The therapeutic approach to Wilms tumor (WT) is multidisciplinary and leads to significant patient impairment, increasing the risk of nutritional compromise and malnutrition. Children with cancer are vulnerable to sarcopenia which has been recognized as a negative impact of anticancer therapy. Recent studies have highlighted the reduction in the total psoas muscle area (TPMA) to be associated with a poor prognosis in many pediatric diseases, including cancer. This study aims to evaluate changes in the TPMA compartment during the treatment of children with WT. An observational, longitudinal, and retrospective study was undertaken in a single institution evaluating children (1 to 14 y, n=38) with WT between 2014 and 2020. TPMA was assessed by the analysis of previously collected, electronically stored computed tomography images of the abdomen obtained at 3 time points: diagnosis, preoperatively, and 1 year after surgery. For all patients, TPMA/age were calculated with a specific online calculator. Our data show a high incidence of sarcopenia (55.3%) at diagnosis which increased after 4 to 6 weeks of neoadjuvant chemotherapy (73.7%) and remained high (78.9%) 1 year after the surgical procedure. Using TPMA/age Z-score curves we have found significant and rapid muscle loss in children with WT, with little or no recovery in the study period.

Magnetic Resonance Imaging Can Be Used to Assess Sarcopenia in Children with Newly Diagnosed Crohn's Disease

BACKGROUND

This study aimed to determine the proportion of patients with sarcopenia diagnosed by MRI and compare these results to bioelectrical impedance analysis (BIA).

METHODS

Children with newly diagnosed Crohn's disease (CD) who had MRI enterography (MRE) and BIA and had at least 12 months of follow-up were included. Total psoas muscle area (TPMA) and total paravertebral muscle (TPVM) were measured and compared to subjects' lean mass and the lean mass body index (LMBI) was assessed by BIA.

RESULTS

30 newly diagnosed children with CD were included (mean age 14.2 years, 53% male). Sarcopenia was found in 13 (43%) children; mean TPMA was 15.2 (1.1 SD) cm2 and TPVM 30.95 (1.7 SD) cm2. A highly positive correlation was shown for lean mass assessed by BIA and TPMA (0.706, p < 0.001) and TPVM (0.75, p < 0.001). Sarcopenia was more prevalent in boys (77% vs. 24%, p = 0.004), patients with the perianal disease (69% vs. 29%, p = 0.03), and children with sarcopenia were likely to receive anti-TNF (77% vs. 41%, p = 0.05). During the follow-up period, 16 (53%) children experienced a relapse. TPMA (HR 0.99, p = 0.018) and TPVM (HR 0.99, p = 0.031) values were statistically significant risk factors for relapse.

CONCLUSION

A high proportion of patients with CD have sarcopenia at the time of the diagnosis. There is a good correlation between muscle mass assessed by MRI and BIA. Because MRI is performed in a great proportion of newly diagnosed CD patients it can also be used to assess the presence of sarcopenia.

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.

Decrease of Muscle Mass in Young Patients With Neuromuscular Disease: Assessment of Sarcopenia

BACKGROUND

Sarcopenia can be associated with the disease etiologies other than degenerative processes, such as neurologic disease including cerebral palsy, myelomeningocele, or Duchenne muscular dystrophy, even in children. Although the relationship between neurologic disease and scoliosis or ambulatory function is known, the mediators affecting scoliosis or gait function in these patients are unclear, an example might be sarcopenia. This study aimed to assess the degree of sarcopenia in young patients with neurologic diseases using computed tomography (CT), and analyze the correlation between sarcopenia and scoliosis or ambulatory function.

METHODS

Pediatric and young adult patients (≤ 25 years old) who underwent whole-spine or lower-extremity CT were retrospectively included. From bilateral psoas muscle areas (PMAs) at the L3 level, the psoas muscle z-score (PMz) and psoas muscle index [PMI = PMA/(L3 height)²] were calculated. The t-test, Fisher's exact test, and logistic regression analyses were performed.

RESULTS

A total of 121 patients (56 men, mean age 12.2 ± 3.7 years) were included with 79 neurologic and 42 non-neurologic diseases. Patients with neurologic diseases had lower PMz (P = 0.013) and PMI (P = 0.026) than patients without. In neurologic disease patients, severe scoliosis patients showed lower PMz (P < 0.001) and PMI (P = 0.001). Non-ambulatory patients (n = 42) showed lower BMI (β = 0.727, P < 0.001) and PMz (β = 0.547, P = 0.025). In non-ambulatory patients, patients with severe scoliosis also showed lower PMz (P < 0.001) and PMI (P = 0.004).

CONCLUSION

Patients with neurologic diseases could have sarcopenia even in young age. Psoas muscle volume was also associated with ambulatory function in these patients. Sarcopenia was more severe in severe scoliosis patients in the non-ambulatory subgroup.

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.

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.

Sarcopenia - Definition, Radiological Diagnosis, Clinical Significance

BACKGROUND

 Sarcopenia is an age-related syndrome characterized by a loss of muscle mass and strength. As a result, the independence of the elderly is reduced and the hospitalization rate and mortality increase. The onset of sarcopenia often begins in middle age due to an unbalanced diet or malnutrition in association with a lack of physical activity. This effect is intensified by concomitant diseases such as obesity or metabolic diseases including diabetes mellitus.

METHOD

 With effective preventative diagnostic procedures and specific therapeutic treatment of sarcopenia, the negative effects on the individual can be reduced and the negative impact on health as well as socioeconomic effects can be prevented. Various diagnostic options are available for this purpose. In addition to basic clinical methods such as measuring muscle strength, sarcopenia can also be detected using imaging techniques like dual X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI), and sonography. DXA, as a simple and cost-effective method, offers a low-dose option for assessing body composition. With cross-sectional imaging techniques such as CT and MRI, further diagnostic possibilities are available, including MR spectroscopy (MRS) for noninvasive molecular analysis of muscle tissue. CT can also be used in the context of examinations performed for other indications to acquire additional parameters of the skeletal muscles (opportunistic secondary use of CT data), such as abdominal muscle mass (total abdominal muscle area - TAMA) or the psoas as well as the pectoralis muscle index. The importance of sarcopenia is already well studied for patients with various tumor entities and also infections such as SARS-COV2.

RESULTS AND CONCLUSION

 Sarcopenia will become increasingly important, not least due to demographic changes in the population. In this review, the possibilities for the diagnosis of sarcopenia, the clinical significance, and therapeutic options are described. In particular, CT examinations, which are repeatedly performed on tumor patients, can be used for diagnostics. This opportunistic use can be supported by the use of artificial intelligence.

KEY POINTS

· Sarcopenia is an age-related syndrome with loss of muscle mass and strength.. · Early detection and therapy can prevent negative effects of sarcopenia.. · In addition to DEXA, cross-sectional imaging techniques (CT, MRI) are available for diagnostic purposes.. · The use of artificial intelligence (AI) offers further possibilities in sarcopenia diagnostics..

CITATION FORMAT

· Vogele D, Otto S, Sollmann N et al. Sarcopenia - Definition, Radiological Diagnosis, Clinical Significance. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1990-0201.

The impact of sarcopenia and sarcopenic obesity on survival in children with Ewing sarcoma and osteosarcoma

BACKGROUND

Sarcopenia is an indicator of negative outcomes in many diseases in adults. Reports indicate this might also be true in children.

OBJECTIVE

To evaluate the effect of sarcopenia and sarcopenic obesity on event-free survival (EFS) and overall survival (OS) in children with Ewing sarcoma and osteosarcoma.

MATERIALS AND METHODS

We retrospectively measured total muscle areas of the pectoralis, paraspinal (T12 level) and psoas (L4 level) muscles and total abdominal muscle area (L3 level) on computed tomography images in 60 children diagnosed with either Ewing sarcoma (n = 34) or osteosarcoma (n = 26). Skeletal muscle indices (SMI) were calculated by normalizing muscle area to patient height. Vertebral morphologic parameters of T12 and L4 vertebrae were measured and correlated to patient height to use as a substitute in cases of missing height data (SMI_T12 and SMI_L4). We calculated sarcopenic obesity index by dividing SMI by body mass index. We subdivided children into two groups according to the median value of each parameter and assessed the differences in survival between the groups.

RESULTS

No skeletal muscle index or sarcopenic obesity index parameter significantly affected event-free or overall survival in the total group analysis. In the non-metastatic group, higher values of SMI-paraspinal and SMI_T12-psoas were correlated with longer event-free survival and no patient died in this group. Boys and children in the metastatic group with higher SMI_T12-paraspinal values had significantly longer event-free survival and both event-free and overall survival, respectively.

CONCLUSION

Although some parameters were correlated with event-free and overall survival, neither sarcopenia nor sarcopenic obesity were reliably associated with survival in children with Ewing sarcoma or osteosarcoma.

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.

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.

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.

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 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.

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: 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% to 95% age-based percentiles using CDC and WHO growth charts), known medical condition, medication use, support devices, surgery, or missing axial images at L3 level. A previously validated automated DL pipeline (https://github.com/cchmc-dll/pediatric_sarcopenia_pipeline.git) 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, 11.5±45 years; 1125 females, 1043 males) met inclusion criteria. Mean BMI-for-age percentile based on CDC and WHO growth charts was 64.8±25.3% for females and 61.4±25.8% for males. SMA showed strong correlation with weight, height, age, and BMI for males (0.79-0.94) and females (0.75-0.90); SMI showed weak-to-moderate correlation with weight, height, age and BMI for males (0.25-0.57) and females (0.00-0.43). Normal SMA and SMI ranges for age and sex were expressed as curves and as a lookup table, identifying 54 males and 59 females with muscle measurements below the 5-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.

Malnutrition in Biliary Atresia: Assessment, Management, and Outcomes

Children with biliary atresia (BA), particularly infants, are at high risk for malnutrition attributed to a multitude of factors, including poor oral intake and intolerance of enteral feeding, fat malabsorption, abnormal nutrient metabolism, and increased caloric demand. Malnutrition and sarcopenia negatively impact outcomes in BA, leading to higher pretransplant and posttransplant morbidity and mortality. This review summarizes factors contributing to nutritional deficiencies in BA and offers an organized approach to the assessment and management of malnutrition in this vulnerable population.

Sarcopenia is highly prevalent in children with autoimmune liver diseases and is linked to visceral fat and parent-perceived general health

BACKGROUND

Patients with autoimmune hepatitis (AIH) and primary or autoimmune sclerosing cholangitis are at nutritional risk; their body composition and has not been extensively studied. We aimed to describe their body composition and identify clinical links.

METHODS

Using magnetic resonance imaging (MRI), two reviewers segmented total psoas muscle area (tPMSA), visceral fat area (VFA) and subcutaneous fat area (mm² ) and measured visceral and subcutaneous thickness (mm). Clinical, laboratory and quality of life (QoL; using PedsQL) data were collected. Sarcopenia was defined as tPMSA ≤5th percentile. Analysis of variance, Wilcoxon rank test and multivariable modelling were performed. A paediatric cohort with non-alcoholic fatty liver disease (NAFLD) was used as a comparator following propensity score matching.

RESULTS

Fifty-eight patients with autoimmune liver disease (AILD) (33 [57%] with AIH) were included: median age 16 years (interquartile range [IQR]: 13-18), 33 (57%) male. Median time from diagnosis to MRI was 15 months (IQR: 2-39 months). Two patients (3%) had a BMIz indicative of mild malnutrition. tPMSA was measurable in 52 subjects (90%). Of those, 25 (48%) had sarcopenia. Sarcopenic patients had a lower blood urea nitrogen compared to non-sarcopenic (median [IQR]: 9.5 [8.0, 12.0] vs 11 [10, 14] mg/dL; P = .023). There was no difference in corticosteroid use between groups. The VFA of sarcopenic patients was higher (3156 [2064, 7492]) vs 2084 [688, 3092]) mm² ; P = .005). Patient-reported QoL negatively associated with VFA and general health negatively associated with VFA. Compared with NAFLD, the odds ratio for sarcopenia with AILD was 14.5 (95% confidence interval: 2.3-90.7).

CONCLUSION

In autoimmune liver diseases, sarcopenia is highly prevalent, associated with increased visceral fat and QoL.

Clinical Impact of Nutritional Status and Sarcopenia in Pediatric Patients with Bone and Soft Tissue Sarcomas: A Pilot Retrospective Study (SarcoPed)

Background: We evaluated nutritional and sarcopenia status and their clinical impact in pediatric patients affected by bone and soft tissue sarcomas. Methods: Body mass index (BMI), prognostic nutritional index (PNI), and total psoas muscle area (tPMA) at diagnosis and after 12 months were analyzed. tPMA was measured from single cross-sectional computed tomography (CT) images at L4–L5. Age-specific and sex-specific tPMA Z-scores were retrieved from an online calculator. Results: A total of 21 patients were identified between February 2013 and December 2018. Twelve patients (57.1%) experienced sarcopenia at diagnosis, although not statistically associated with overall survival (OS) (p = 0.09). BMI Z-score, PNI, and tPMA Z-score significantly decreased between diagnosis and after 12 months of treatment (p < 0.05). Univariate analysis showed significant associations between poor OS and the presence of metastasis (p = 0.008), the absence of surgery (p = 0.005), PNI decrease (p = 0.027), and the reduction in tPMA > 25% (p = 0.042) over the 12 months. Conclusions: Sarcopenia affects more than half of the patients at diagnosis. Decreased PNI during 12 months of treatment has significant predictive value for OS. The role of tPMA derived from CT scan among pediatric patients with sarcoma should be investigated in further prospective and larger studies.

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.

Skeletal muscle mass as a marker to predict outcomes in children and young adults with cancer

PURPOSE

Nutrition is an important outcome predictor in oncology patients including treatment response, physical disability, quality of life, and overall survival. Sarcopenia (loss of skeletal muscle mass and function) is a demonstrated marker of nutritional status in adults, but data are more limited in children. The purpose of this study was to evaluate whether total psoas muscle area (tPMA) measured at the time of cancer diagnosis predicts overall survival (OS), disease free survival (DFS), or number of days neutropenic.

METHODS

A retrospective study was performed. tPMA was measured at the L3 and L4 mid-lumbar vertebral body level by a single reviewer on cross-sectional imaging studies performed within 2 weeks of primary oncologic diagnosis for all oncology patients who received their primary therapy at Cincinnati Children's Hospital between 1/1/2000 and 12/31/2013. Spearman's correlation was used to assess the association between tPMA and OS, DFS, days neutropenic, and adjusted days neutropenic. Subanalysis was performed assessing the relationship of tumor type and age at diagnosis with each parameter.

RESULTS

164 patients (median age 9.9 years; 89 M/75 F) were included in the study. Days neutropenic and normalized days neutropenic were significantly but weakly negatively correlated with tPMA at L3 (r =  - 0.24, p < 0.002 and r =  - 0.18, p < 0.05 respectively) and L4 (r =  - 0.25, p < 0.002; and and r =  - 0.19, p < 0.02 respectively). At subanalysis, the correlation between anthropometric features and normalized days neutropenic was only seen with brain tumors. There was no statistically significant relationship between sarcopenia at diagnosis and DFS or OS overall or in subanalysis.

CONCLUSION

There is a weak inverse relationship between days neutropenic and psoas muscle bulk in pediatric and young adult oncology patients suggesting a relationship between nutritional status and cell recovery. Measures of sarcopenia, however, did not correlate with DFS or OS.

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.

Does sarcopenia affect outcomes in pediatric surgical patients? A scoping review

OBJECTIVE

Adults with sarcopenia have a greater risk of postoperative complications, a higher rate of ICU admission, and an increased length of hospital stay. Few studies have explored the prevalence or importance of sarcopenia in the pediatric population. This study reviews the published literature on sarcopenia in the pediatric population, including pediatric surgery.

METHODS

Original studies related to sarcopenia in children were identified using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines and the PubMed database.

RESULTS

A total of 390 articles were screened, with 28 meeting inclusion criteria. Twenty (71%) studies provided a means to define abnormal and 18 studies (64%) showed that a specific disease process could impact lean muscle mass in children. Only 4 (14%) studies associated the change in muscle mass with an outcome. Two studies investigated sarcopenia and outcomes in the pediatric surgical patient and demonstrated associations with worse outcomes.

CONCLUSION

Despite studies showing an association between sarcopenia and negative outcomes in the adult surgical population, there remains a paucity of evidence regarding the impact of sarcopenia on the pediatric population. Future studies are needed to ascertain the relationship between muscle mass and outcomes in pediatric surgical patients.

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.

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.