Improvement of BMI after Lifestyle Intervention Is Associated with Normalisation of Elevated ELF Score and Liver Stiffness in Obese Children

BACKGROUND Noninvasive tools to diagnose nonalcoholic fatty liver disease (NAFLD), including transient elastography (TE) and enhanced liver fibrosis panel (ELF), have only been evaluated in children with biopsy-proven NAFLD. We evaluated the prevalence of ELF and TE abnormalities in obese children without clinical liver disease and examined the effects of BMI stabilization on ELF and TE in a longitudinal approach. METHODS 39 obese children (17 m, age 12.3 (7.6-17.4) years) who participated in a 12-month lifestyle-intervention program underwent TE and ELF testing at baseline and at completion of the program. Results were compared with data from a nonobese paediatric cohort. RESULTS TE and ELF at baseline were significantly elevated compared to controls (TE: 5.9 (3.4-8.3) kPa versus 4.45 (2.45-8.85) kPa, P < 0.01; ELF: 9.0 (7.87-9.60) versus 8.6 (7.33-11.52), P = 0.033). All children with elevated TE and ELF results had normal transaminases. After the program, ELF and TE normalized. Reduction of ELF and TE was associated with a decrease in BMI centile. CONCLUSION Abnormal TE and ELF results in obese children suggest presence of NAFLD even when transaminases are normal. TE and ELF might be used as monitoring tools for NAFLD. BMI stabilisation normalizes TE and ELF, underlining the impact of lifestyle intervention.