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

BACKGROUND: Malnutrition is a common complication in children with chronic diseases. Sarcopenia is one component of malnutrition, characterized by reduced skeletal muscle mass (SMM) and muscle function. The presence of sarcopenia is associated with adverse outcomes in children. Although there is growing research interest in sarcopenia, no review has been done on this novel concept in pediatrics. The purpose of this review was to explore current evidence in sarcopenia with and without obesity and to evaluate the knowledge gaps in the assessment of childhood sarcopenia. METHODS: A total of 12 articles retrieved from PubMed or Web of Science databases were included. RESULTS: Limited studies have elucidated sarcopenia in pediatrics. Challenges in sarcopenia assessment include heterogeneity in definition and absence of standardized body composition methods used to measure SMM and muscle function tests. There is a lack of age-specific and gender-specific normative data for SMM, particularly in young children and infants. None of the studies incorporated muscle function assessment, causing potential bias and misclassification of sarcopenia. The research in childhood sarcopenia is also hampered by low study quality, limited number of outcomes-based research, and lack of longitudinal data. CONCLUSION: Consensus needs to be reached in methodological approaches in sarcopenia diagnosis, body composition measurements, and age-appropriate muscle function tests in pediatrics. Careful considerations on growth, neurocognitive status, and factors influencing development in various clinical populations are warranted. Early identification of sarcopenia is crucial to enable targeted treatment and prevention to be carried out across the pediatric clinical populations.