Determination of reference values for abdominal skeletal muscle compartments in Turkish children.

BackgroundSarcopenia, defined by reduced muscle strength and low muscle mass, is associated with chronic diseases, malnutrition, and growth retardation in children. Computed tomography (CT) is considered the gold standard for assessing skeletal muscle mass. However, pediatric reference values for abdominal skeletal muscle area (aSMA) at lumbar vertebral levels remain limited and vary among populations.ObjectiveTo establish age- and sex-specific reference values and percentile curves for aSMA, including psoas muscle area (PMA), paraspinal muscle area (PSMA), and total skeletal muscle area (TSMA), at L3 vertebral body, L3-L4 and L4-L5 intervertebral disc levels in Turkish children.MethodsThis retrospective study included 2166 Turkish children aged 0-18 years who underwent abdominal CT scans for acute indications. aSMA measurements were obtained at three lumbar levels, and percentile curves were calculated using the Lambda-Mu-Sigma method. SD intervals of ±2 were determined for each parameter. Children with chronic diseases or abnormal muscle morphology were excluded.ResultsOf the participants, 62.1% were boys and 37.9% were girls, with a median age of 10 years (IQR: 5-15). Age- and sex-specific percentile values (3rd-97th) and ±2 SD ranges were established for PMA, PSMA, and TSMA. At the L3-L4 intervertebral disc level, the PMA (50th percentile) ranged from 3.3-15.4 cm² in girls and 3.3-27.2 cm² in boys. Comparative analysis with other populations showed significant inter-population differences.ConclusionWe establish level-specific (L3, L3-L4, L4-L5) normative charts-3rd-97th percentiles and ±2 SD limits-for PMA, PSMA, and TSMA in Turkish children aged 0-18 years, providing population-specific benchmarks that standardize abdominal skeletal muscle assessment and support early identification of low muscle area.