Nonalcoholic Fatty Liver Disease in Taiwanese Children

Study Subjects Obesity was defined as the BMI value > 95 percentile by different age- and gender groups according to the standards of the Department of Health in Taiwan. All participants' parents gave their informed consent, and the study was approved by the ethics committee of the Far Eastern Memorial Hospital.

Data Collection The following data were obtained for each subject: age, gender, BMI, waist and hip circumference. BMI was calculated as body weight (kg)/ height (m2). The ratio between waist and hip circumference was calculated and referred to as the waist-to-hip ratio (WHR).

In fasting venous blood samples, we measured total serum bilirubin, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, fasting glucose, triglyceride, total cholesterol and high-density lipoprotein cholesterol. Insulin levels were measured using chemiluminescence immunoassay (DPC, Los Angeles, CA, USA). CRP levels were measured with the use of an immunonephelometry assay (Dade Behring Inc, Newark, USA). Serum adiponectin was determined by an ELISA kit (B-bridge, Tokyo, Japan). Insulin resistance was measured by the homeostasis model assessment of insulin resistance (HOMA-IR) and was calculated as follows: HOMA-IR = (fasting insulin [μU/mL])(fasting glucose [mmol/L]/22.5).

Liver Ultrasonography All participants underwent an ultrasonographic study of the liver performed by one operator. The hand-carried machine used (TITAN®, SonoSite Ltd, United Kingdom) was equipped with a 2-5 MHz convex probe.

NAFLD was defined as the presence of an ultrasonographic pattern consistent with the following criteria: liver-kidney echo discrepancy, attenuated echo penetration and visibility of diaphragm, and obscure hepatic vessel structures. The above-mentioned ultrasonographic pattern was scored as described by Chan et al. A score > 4 was used as the diagnostic criterion for pediatric NAFLD in this study.