Utility of muscle ultrasound in nutritional assessment of children with nephrotic syndrome

BACKGROUND: Nutritional status assessment in children with nephrotic syndrome (NS) is critical for identifying patients who are at risk of protein-energy wasting (PEW) and for determining their nutritional needs and monitoring nutritional intervention outcomes. METHODS: In a case–control study, we enrolled 40 children (age range: 2–16 years) with NS and 40 apparently healthy children (age and sex-matched) as a control group. Anthropometric data, as well as demographic, clinical, and laboratory data, were collected. A dietary intake assessment using a 3-day food intake record was done, and the quadriceps rectus femoris thickness (QRFT) and quadriceps vastus intermedius thickness (QVIT) were assessed using B-mode ultrasound and compared between both groups. RESULTS: Children with NS had lower QRFT and QVIT measurements than control groups (p < 0.001). Inadequacy in protein intake occurred in 62.5% and 27.5% of the NS and control groups, respectively (p = 0.002). The thickness of the rectus and vastus muscles by ultrasound was significantly associated with the percentage of protein intake (p < 0.001). The ROC curve revealed that the best cutoff value of QRFT for the prediction of the patient at risk of malnutrition was ≤ 1.195 with an area under curve of 0.907, with p < 0.001. CONCLUSION: In children with NS, skeletal muscle ultrasound is a simple and easy-to-use bedside technique for the identification of patients at risk of malnutrition. GRAPHICAL ABSTRACT: [Figure: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00467-022-05776-y.