Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 21, 2020; 26(15): 1792-1804
Published online Apr 21, 2020. doi: 10.3748/wjg.v26.i15.1792
Prevalence, clinical characteristics, risk factors, and indicators for lean Chinese adults with nonalcoholic fatty liver disease
Jing Zeng, Rui-Xu Yang, Chao Sun, Qin Pan, Rui-Nan Zhang, Guang-Yu Chen, Ying Hu, Jian-Gao Fan
Jing Zeng, Rui-Xu Yang, Chao Sun, Qin Pan, Rui-Nan Zhang, Ying Hu, Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
Guang-Yu Chen, Clinical Epidemiology Research Center, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
Jian-Gao Fan, Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Children’s Digestion and Nutrition, Shanghai 200092, China
Author contributions: Zeng J and Yang RX contributed equally to this work; Zeng J, Yang RX, and Zhang RN carried out the experiments; Zeng J, Yang RX, Sun C, Pan Q, and Chen GY contributed to acquisition, analysis, or interpretation of the data; Zeng J and Yang RX wrote the paper; Hu Y and Fan JG made critical revision of the manuscript for important intellectual content.
Supported by National Key R&D Program of China, No. 2017YFC0908900; National Natural Science Foundation of China, No. 81873565 and No. 81900507; Hospital Funded Clinical Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, No. 17CSK04 and No. 15LC06.
Institutional review board statement: The study was reviewed and approved by the ethics committees of all hospitals involved. All procedures were performed in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008.
Informed consent statement: Informed consent was obtained from all individual participants included in the study.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Jian-Gao Fan, MD, PhD, Professor, Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Children’s Digestion and Nutrition, No. 1665, Kongjiang Road, Yangpu District, Shanghai 200092, China. fanjiangao@xinhuamed.com.cn
Received: December 25, 2019
Peer-review started: December 25, 2019
First decision: January 19, 2020
Revised: March 19, 2020
Accepted: March 27, 2020
Article in press: March 27, 2020
Published online: April 21, 2020
Abstract
BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic diseases in the world. Nowadays, the percentage of non-obese or lean patients with NAFLD is increasing. NAFLD in non-obese populations, especially the lean subgroup with a normal waist circumference (WC), might lead to more problems than obese individuals, as these individuals may not visit clinics for NAFLD diagnosis or ignore the diagnosis of NAFLD. If the precise characteristics of these populations, especially the lean subgroup, are identified, the clinicians would be able to provide more appropriate advice and treatment to these populations.

AIM

To investigate the prevalence, clinical characteristics, risk factors, and possible indicators for NAFLD in lean Chinese adults with a normal WC.

METHODS

People without diabetes mellitus or significant alcohol consumption who underwent routine health examinations were included. Their fatty liver index (FLI), abdominal ultrasonography results, and controlled attenuation parameter were all assessed. Genotyping for single-nucleotide polymorphisms associated with NAFLD was performed in another small group consisting of biopsy-proven NAFLD subjects and healthy controls.

RESULTS

A total of 2715 subjects who underwent routine health examinations were included in the study. Among 810 lean participants with a normal WC, 142 (17.5%) fulfilled the diagnostic criteria for NAFLD. Waist-height ratio, hemoglobin, platelets, and triglycerides were significant factors associated with the presence of NAFLD in these participants. The appropriate cut-off value of the FLI score in screening for NAFLD in the lean subjects with a normal WC was 25.15, which had a 77.8% sensitivity and 75.9% specificity. There was no significant difference in the single-nucleotide polymorphisms in the SIRT1, APOC3, PNPLA3, AGTR1, and PPARGC1A genes between lean subjects with and without NAFLD (P < 0.05).

CONCLUSION

NAFLD is not uncommon in lean Chinese adults even with a normal WC. Metabolic factors, rather than genetic factors, may play important roles in the development of NAFLD in this population. A lower cut-off value of the FLI score in screening for NAFLD should be used for lean Chinese adults with a normal WC.

Keywords: Non-alcoholic fatty liver disease, Lean, Body max index, Waist circumference, Fatty liver index, Triglyceride

Core tip: The precise characteristics of nonalcoholic fatty liver disease (NAFLD) in lean Chinese adults with a normal waist circumference (WC) remain unclear. Therefore, we aimed to investigate the prevalence, clinical characteristics, risk factors, and possible indicators for NAFLD in this population. Among 810 lean participants with a normal WC, 142 (17.5%) fulfilled the diagnostic criteria for NAFLD. NAFLD is not uncommon in Chinese lean adults even with a normal WC. Metabolic factors, rather than genetic factors, may play important roles in the development of NAFLD in this population. A lower cut-off value of the fatty liver index score in screening for NAFLD should be used for lean Chinese adults with a normal WC.