Ultrasound evaluation of quadriceps muscle thickness and body fat distribution in children receiving maintenance hemodialysis: a cross-sectional case-control study.

UNLABELLED: Children on hemodialysis (HD) are at multifactorial nutritional risk. Nutritional assessment in these children is challenging because conventional anthropometric and dietary indicators are influenced by growth failure, chronic inflammation, and fluid shifts. Ultrasound (US)-based muscle assessment has emerged as a practical bedside method for evaluating muscle mass, while data on US-derived fat distribution in this population are limited. This cross-sectional case-control study was conducted at a tertiary HD center and enrolled 42 children on HD and 42 age- and sex-matched apparently healthy children. Demographic, anthropometric, clinical, and laboratory data were collected. Dietary evaluation using a 3-day food intake record was performed. Quadriceps muscle thickness, primarily that of the rectus femoris (RF), was assessed using B-mode muscle US in both groups. Subcutaneous thigh fat, anterior abdominal fat, and visceral fat thickness (VFT) were also assessed to characterize body composition. Total daily calorie intake and protein intake were significantly lower in children on HD (p < 0.001). Children on maintenance HD had significantly lower peripheral muscle thickness than healthy controls. Subcutaneous fat thickness at the thigh and abdominal wall was significantly reduced, whereas VFT was significantly increased in the HD group (p < 0.05). Correlation analysis showed that total caloric and protein intake were positively associated with muscle thickness (p < 0.001). Receiver operating characteristic (ROC) curve analysis showed that RF thickness demonstrated moderate discriminatory ability for nutritional risk, with an area under the curve (AUC) of 0.731 (p < 0.001), whereas US-derived fat measurements showed limited diagnostic performance.

CONCLUSION: Quadriceps muscle US appears to be a practical adjunct and complementary assessment tool to conventional nutritional assessment in children receiving maintenance HD. US-derived subcutaneous and visceral fat measurements provide complementary information on body composition and fat distribution.

WHAT IS KNOWN: • Children receiving maintenance hemodialysis are at high risk of nutritional impairment, growth failure, and altered body composition, making nutritional assessment challenging. • Ultrasound assessment of quadriceps muscle thickness is a practical bedside method for evaluating muscle mass in adults receiving hemodialysis, but pediatric evidence remains limited.

WHAT IS NEW: • This study highlights the utility of bedside US measurement of quadriceps muscle thickness as a practical adjunct for detecting nutritional risk in children on maintenance HD. • This study provides novel pediatric data on US-derived subcutaneous and VFT in children on maintenance HD, revealing an altered fat distribution pattern characterized by reduced peripheral fat and increased visceral fat.