Observational Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 28, 2015; 21(20): 6287-6295
Published online May 28, 2015. doi: 10.3748/wjg.v21.i20.6287
Cholecystectomy is independently associated with nonalcoholic fatty liver disease in an Asian population
Min-Sun Kwak, Donghee Kim, Goh Eun Chung, Won Kim, Yoon Jun Kim, Jung-Hwan Yoon
Min-Sun Kwak, Donghee Kim, Goh Eun Chung, Department of Internal Medicine, Healthcare Research Institute, Healthcare System Gangnam Center, Seoul National University Hospital, Seoul 135-984, South Korea
Won Kim, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul 135-984, South Korea
Yoon Jun Kim, Jung-Hwan Yoon, Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul 135-984, South Korea
Author contributions: Kim D contributed to the conception and design of the study; Kwak MS and Kim D contributed to the acquisition, analysis and interpretation of the data and wrote the paper; Chung GE, Kim W, Kim YJ, and Yoon JH contributed to the acquisition of the data and reviewed the paper.
Supported by Seoul National University Hospital Research Fund, No. 04-2014-0660.
Ethics approval: The study was reviewed and approved by the Institutional Review Board of Seoul National University Hospital, No. H1309-019-518.
Informed consent: The need to obtain informed consent from the subjects was waived by the Institutional Review Board of Seoul National University Hospital.
Conflict-of-interest: The authors have no conflicts of interest to declare. The funding organizations played no role in the design and conduct of the study, the collection, analysis, and interpretation of the data, or in the writing, review, and approval of the manuscript.
Data sharing: The technical appendix, statistical code and dataset are available from the corresponding author at messmd@chol.com. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Donghee Kim, MD, PhD, Department of Internal Medicine, Healthcare Research Institute, Healthcare System Gangnam Center, Seoul National University Hospital, Seoul 135-984, South Korea. messmd@chol.com
Telephone: +82-2-21125574 Fax: +82-2-21125635
Received: December 3, 2014
Peer-review started: December 5, 2014
First decision: January 22, 2015
Revised: February 9, 2015
Accepted: April 3, 2015
Article in press: April 3, 2015
Published online: May 28, 2015
Processing time: 177 Days and 18.1 Hours
Abstract

AIM: To investigate the relationship between gallstone disease and nonalcoholic fatty liver disease (NAFLD) in a large Asian population.

METHODS: A cross-sectional study including 17612 subjects recruited from general health check-ups at the Seoul National University Hospital, Healthcare System Gangnam Center between January 2010 and December 2010 was conducted. NAFLD and gallstone disease were diagnosed based on typical ultrasonographic findings. Subjects who were positive for hepatitis B or C, or who had a history of heavy alcohol consumption (> 30 g/d for men and > 20 g/d for women) or another type of hepatitis were excluded. Gallstone disease was defined as either the presence of gallstones or previous cholecystectomy, and these two entities (gallstones and cholecystectomy) were analyzed separately. Clinical parameters including body mass index, waist circumference, hypertension, diabetes, smoking status, and regular physical activity were reviewed. Laboratory parameters, including serum levels of gamma-glutamyl transpeptidase, alanine aminotransferase, aspartate aminotransferase, fasting glucose, fasting insulin, total cholesterol, triglycerides, and high-density lipoprotein, were also reviewed.

RESULTS: The mean age of the subjects was 48.5 ± 11.3 years, and 49.3% were male. Approximately 30.3% and 6.1% of the subjects had NAFLD and gallstone disease, respectively. The prevalence of gallstone disease (8.3% vs 5.1%, P < 0.001), including both the presence of gallstones (5.5% vs 3.4%, P < 0.001) and a history of cholecystectomy (2.8% vs 1.7%, P < 0.001), was significantly increased in the NAFLD group. In the same manner, the prevalence of NAFLD increased with the presence of gallstone disease (41.3% vs 29.6%, P < 0.001). Multivariate regression analysis showed that cholecystectomy was associated with NAFLD (OR = 1.35, 95%CI: 1.03-1.77, P = 0.028). However, gallstones were not associated with NAFLD (OR = 1.15, 95%CI: 0.95-1.39, P = 0.153). The independent association between cholecystectomy and NAFLD was still significant after additional adjustment for insulin resistance (OR = 1.45, 95%CI: 1.01-2.08, P = 0.045).

CONCLUSION: This study shows that cholecystectomy, but not gallstones, is independently associated with NAFLD after adjustment for metabolic risk factors. These data suggest that cholecystectomy may be an independent risk factor for NAFLD.

Keywords: Fatty liver; Hepatic steatosis; Gallbladder; Cholelithiasis; Gallbladder removal

Core tip: The relationship between gallstone disease (gallstones and cholecystectomy, separately) and ultrasonographically diagnosed nonalcoholic fatty liver disease (NAFLD) was analyzed in a large Asian population. The prevalence of gallstone disease increased with the presence of NAFLD, and the prevalence of NAFLD increased with the presence of gallstone disease. Multivariate regression analysis showed that cholecystectomy was associated with NAFLD. However, gallstones were not associated with NAFLD. The independent association between cholecystectomy and NAFLD was still significant after additional adjustment for insulin resistance. This study showed that cholecystectomy, but not gallstones, is independently associated with NAFLD after adjustment for metabolic risk factors.