S1331 Comparison of Liver Elastography Between Obese and Non-Obese Children: A Systematic Review and Meta-Analysis

Abstract

Introduction: Non-invasive Liver fibrosis evaluation in suspected NAFLD has been studied in obese adults, but few studies have addressed the utility of Transient and Shear-wave Elastography assessing early-stage fibrosis in pediatric population. We aimed to perform a systematic review and meta-analysis to compare Liver Elastography findings between obese and non-obese children. Methods: PubMed, MEDLINE (OVID), Cochrane Library, Embase, Scopus and Web of Science were searched from inception to January 2022 to identify manuscripts that evaluated Liver steatosis/Liver fibrosis on Elastography (Transient or Shear-wave) in obese children compared to non-obese children. Case series, case reports, editorials, and reviews were excluded. Two independent reviewers extracted data. Disagreements were resolved by a third author. Meta-analyses were performed using a random-effect model with the inverse variance method. We used the Paule-Mandel estimator and Hartung-Knapp-Sidik-Jonkman method for τ2 and 95% confidence intervals calculation. For continuous outcomes we used the Mean Difference (MD). Heterogeneity was assessed by the inconsistency index (I2). Results: Among 3182 articles identified, 17 studies were identified for full text review. Five studies were deemed eligible for inclusion with perfect agreement between investigators (kappa=1.0). A total of 296 obese children and 528 non-obese controls were included in the studies (Table). Three studies used Shear-wave Elastography, four used Transient Elastography and one used both. The female proportion was higher in the non-obese group. ALT and AST values were higher in the obese group in most of the studies. On the non-stratified meta-analysis obese children were found to have higher values of Liver Stiffness Measurement (LSM) measured in kilopascals (kPa) compared with non-obese controls (MD: 1.80, 95% CI: 0.27 - 3.34), however, when stratifying this effect was only significant when using only Transient Elastography (MD: 1.49, 95%: 0.16 - 2.82) (Figure). Conclusion: Our systematic review and meta-analysis demonstrates that obese children present higher values of Liver Stiffness compared to non-obese children. In that sense, this non-invasive testing could be successfully applied as a predictor of NAFLD in the clinical setting. These findings may depend on the elastography type, since it was significant using the Transient Elastography, and more studies are needed to further validate this non-invasive testing.Figure 1.: Forest plot of the effect in Liver stiffness Measurement (kPa) Table 1. - Baseline Characteristics of Included Subjects Study Group Sample size Age (years) Female % ALT AST Total Cholesterol Triglycerides Saglam (2021) Obese 41 11.4 (9.6-13.5) 46.3% 18 (15-22) 21 (19-23) 156 (142-172.75) mg/dl 107.5 (87-135.5) mg/dl Non-obese 25 11.7 (9-13.2) 52% 13 (10.1-16.2) 23 (17.7-25.3) 137.5 (128-149.75) mg/dl 68 (59.25-98.25) mg/dl Zeng Fansen (2020) Obese 67 10.9 (6-17.4) 28.4% 59 (23-101) 32 (21-58) 4.7 (4.3-5.7) mmol/L 1.4 (0.9-1.9) mmol/L Non-obese 139 10.2 (5-17) 41.7% 19 (15-25) 27 (16-34) 3.1 (2.8-3.3) mmol/L 1.1 (0.8-1.3) mmol/L Mărginean (2019) Obese 77 10.4 ± 3.4 33.7% 26.50 ± 43.1 27.33 ± 23.6 NA NA Non-obese 210 11.3 ± 3.83 54.8% 13.64 ± 6.9 22.29 ± 10.9 NA NA Kwon (2019) Obese 59 10.9 ± 2.4 38% 91.27 ± 97.7 57.00 ± 48.5 173.97 ± 37.23 mg/dl NA Non-obese 47 10.1 ± 2.8 40% 16.28 ± 9.8 26.40 ± 11.8 146.65 ± 59.07 mg/dl NA Cho Y (2015) Obese 52 13.0 (3.5-17.6) 26.9% 75 ± 83 48 ± 45 NA 149 ± 73 mg/dl Non-obese 107 11.2 (1.3-17) 49.5% 17 ± 14 24 ± 7 NA 97 ± 65 mg/dl