Longitudinal performance of vibration controlled transient elastography in pediatric metabolic dysfunction associated steatotic liver disease

OBJECTIVES: Vibration controlled transient elastography (VCTE) is increasingly used to monitor metabolic dysfunction-associated steatotic liver disease (MASLD), yet optimal interpretation of serial controlled attenuation parameter (CAP) and liver stiffness measurements (LSMs) in children is undefined. We aimed to characterize longitudinal trends in CAP and LSM and assess whether changes in these measures reflect validated measures of disease regression or progression. METHODS: Longitudinal retrospective study of youth with MASLD who underwent ≥2 VCTE studies. Disease regression and progression were defined using categorical and continuous changes in alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) previously linked to histologic improvement or worsening. Spaghetti plots illustrated trends over time, while longitudinal linear mixed-effects models and proportional odds mixed models assessed associations between CAP, LSM, and liver enzyme outcomes. RESULTS: The cohort included 149 children (72% male, 43% Hispanic) with a mean age of 14 ± 4 years and a mean follow-up of 1.4 years. CAP and LSM showed marked intraindividual variability. Independent predictors of CAP change included age, body mass index (BMI) percentile, and glycated hemoglobin (HbA1c); predictors of LSM change included ALT, BMI, and HbA1c. Changes in CAP and LSM did not predict categorical outcomes of ALT and GGT reduction, however were significantly positively associated with continuous ALT and GGT outcomes, independent of BMI percentile. CONCLUSIONS: Longitudinal VCTE in pediatric MASLD has the potential to identify disease progression. The intraindividual variability of CAP and LSM may limit the ability to detect short-term regression or progression, highlighting the need for more precise noninvasive biomarkers for pediatric MASLD.