Original Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Feb 14, 2011; 17(6): 735-742
Published online Feb 14, 2011. doi: 10.3748/wjg.v17.i6.735
Non-alcoholic fatty liver disease: An early mediator predicting metabolic syndrome in obese children?
Jun-Fen Fu, Hong-Bo Shi, Li-Rui Liu, Ping Jiang, Li Liang, Chun-Lin Wang, Xi-Yong Liu
Jun-Fen Fu, Hong-Bo Shi, Li-Rui Liu, Ping Jiang, Li Liang, Chun-Lin Wang, Department of Endocrinology, The Children’s Hospital of Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
Hong-Bo Shi, Department of Pediatrics, Yinzhou People’s Hospital, Ningbo 315400, Zhejiang Province, China
Ping Jiang, The First People’s Hospital of Hangzhou, Hangzhou 310003, Zhejiang Province, China
Xi-Yong Liu, Clinical and Molecular Pharmacology, City of Hope National Medical Center, Duarte, CA 91009, United States
Author contributions: Fu JF, Shi HB, Liu LR and Jiang P substantially contributed to the conception and design of the study; Fu JF and Shi HB also wrote the manuscript; Wang CL collected and input the data; Liang L interpreted the data; Liu XY performed statistical analysis.
Supported by Zhejiang Provincial Natural Science Foundation, No. Y2080047; funds for Zhejiang Major Medical and Health Science and Technology Program and funds from Ministry of Health, No. WKJ2008-2-026; Major Special Zhejiang Provincial Science and Technology Fund, No. 2008c03002-1; and the National Key Technology R&D Program of China, No. 2009BAI80B01
Correspondence to: Jun-Fen Fu, MD, PhD, Department of Endocrinology, The Children’s Hospital of Zhejiang University School of Medicine, 57 Zhugan Avenue, Hangzhou 310003, China. fjf68@yahoo.com.cn
Telephone: +86-571-87061007 Fax: +86-571-87033296
Received: July 20, 2010
Revised: September 6, 2010
Accepted: September 13, 2010
Published online: February 14, 2011
Abstract

AIM: To investigate if non-alcoholic fatty liver disease (NAFLD) is an early mediator for prediction of metabolic syndrome, and if liver B-ultrasound can be used for its diagnosis.

METHODS: We classified 861 obese children (6-16 years old) into three subgroups: group 0 (normal liver in ultrasound and normal transaminases); group 1 (fatty liver in ultrasound and normal transaminases); and group 2 (fatty liver in ultrasound and elevated transaminases). We measured the body mass index, waist and hip circumference, blood pressure, fasting blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), whole-body insulin sensitivity index (WBISI), lipid profile and transaminases in all the participants. The risk of developing metabolic syndrome (MS) was assessed according to the degree of liver fatty infiltration based on the B-ultrasound examination.

RESULTS: Among the 861 obese children, 587 (68.18%) were classified as having NAFLD, and 221 (25.67%) as having MS. The prevalence of MS in NAFLD children (groups 1 and 2) was 37.64% (221/587), which was much higher than that in non-NAFLD group (group 0, 12.04%) (P < 0.01). There were significantly higher incidences concerning every component of MS in group 2 compared with group 0 (P < 0.05). The incidence of NAFLD in MS patients was 84.61% (187/221), which was significantly higher than that of hypertension (57.46%, 127/221) and glucose metabolic anomalies (22.62%, 50/221), and almost equal to the prevalence of dyslipidemia (89.14%, 197/221). Based on the B-ultrasound scales, the presence of moderate and severe liver fatty infiltration carried a high risk of hypertension [odds ratio (OR): 2.18, 95% confidence interval (95% CI): 1.27-3.75], dyslipidemia (OR: 7.99, 95% CI: 4.34-14.73), impaired fasting glucose (OR: 3.65, 95% CI: 1.04-12.85), and whole MS (OR: 3.77; 95% CI: 1.90-7.47, P < 0.01). The state of insulin resistance (calculated by HOMA-IR and WBISI) deteriorated as the degree of fatty infiltration increased.

CONCLUSION: NAFLD is not only a liver disease, but also an early mediator that reflects metabolic disorder, and liver B-ultrasound can be a useful tool for MS screening.

Keywords: Childhood obesity, Non-alcoholic fatty liver disease, Metabolic syndrome, Liver B ultrasonography