Prospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 6, 2021; 9(19): 5112-5125
Published online Jul 6, 2021. doi: 10.12998/wjcc.v9.i19.5112
Impact of continuous positive airway pressure therapy for nonalcoholic fatty liver disease in patients with obstructive sleep apnea
Haruka Hirono, Kazuhiko Watanabe, Katsuhiko Hasegawa, Masaki Kohno, Shuji Terai, Shogo Ohkoshi
Haruka Hirono, Kazuhiko Watanabe, Katsuhiko Hasegawa, Shogo Ohkoshi, Department of Internal Medicine, The Nippon Dental University School of Life Dentistry at Niigata, Niigata 951-8580, Japan
Masaki Kohno, The Center for Dental Sleep Medicine, The Nippon Dental University Niigata Hospital, Niigata 951-8580, Japan
Shuji Terai, Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata 951-8510, Japan
Author contributions: Hirono H wrote the paper; Ohkoshi S contributed to study conception and design; Hirono H, Watanabe K, Hasegawa K, Kohno M, and Ohkoshi S performed data collection, interpretation and follow-up; Hirono H contributed to data analysis; Ohkoshi S revised the manuscript; Terai S provided research advice; all authors read and approved the final version of the manuscript.
Supported by the Japan Society for the Promotion of Science, No. JP16K09564.
Institutional review board statement: This prospective study was approved by the Ethics Committee of The Nippon Dental University School of Life Dentistry at Niigata, No. ECNG-H-247.
Informed consent statement: Informed consent was obtained from each patient prior to enrollment in this study.
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: No additional data are available.
CONSORT 2010 statement: The authors have read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
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: Haruka Hirono, MD, PhD, Associate Professor, Department of Internal Medicine, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamauracho, Chuo-ku, Niigata 951-8580, Japan. haruka@ngt.ndu.ac.jp
Received: February 25, 2021
Peer-review started: February 25, 2021
First decision: April 18, 2021
Revised: April 28, 2021
Accepted: May 7, 2021
Article in press: May 7, 2021
Published online: July 6, 2021
Processing time: 119 Days and 0.1 Hours
Abstract
BACKGROUND

Obstructive sleep apnea (OSA) has been suggested as an independent risk factor for nonalcoholic fatty liver disease (NAFLD), and continuous positive airway pressure (CPAP) is the first-line therapy for OSA.

AIM

To clarify the efficacy of effective CPAP therapy on NAFLD of OSA patients by serum markers and transient elastography (TE) using FibroScan® (Echosens, Paris, France).

METHODS

We prospectively enrolled 123 consecutive patients with OSA who met the indications for CPAP. Liver fibrosis and steatosis were assessed using TE. Before and after 6 mo of CPAP therapy, serum markers and TE were assessed for all patients. The mean usage rate of CPAP therapy for 6 mo was arbitrarily calculated in each patient and expressed as “mean compliance index” (m-CI).

RESULTS

In 50 OSA patients with NAFLD, both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were significantly decreased after 6 mo of CPAP therapy. Univariate analysis showed that decreased body weight (BW), decreased body mass index (BMI), decreased AST level, decreased hemoglobin A1c, and high m-CI were significantly related with improved ALT level. In multivariate regression model adjusted for quantities of BW change during 6 mo of CPAP therapy, high m-CI tended to improve ALT level (P = 0.051). All 17 OSA patients with NAFLD, high m-CI and no BMI changes showed significant improvements in AST and ALT levels. Meanwhile, no significant changes in TE data or serum fibrosis markers were seen.

CONCLUSION

Some NAFLD could be associated with chronic intermittent hypoxia due to OSA independent of BW changes. In those cases, adequate reoxygenation from effective CPAP therapy may improve NAFLD.

Keywords: Nonalcoholic fatty liver disease; Obstructive sleep apnea; Continuous positive airway pressure; Chronic intermittent hypoxia; Transient elastography

Core Tip: Obstructive sleep apnea (OSA) is a condition of chronic intermittent hypoxia (CIH) during sleep. We evaluated the efficacy of reoxygenation by adequate effective continuous positive airway pressure (CPAP) therapy for liver injury in nonalcoholic fatty liver disease (NAFLD) with OSA patients. The results indicate that effective CPAP therapy for 6 mo in OSA patients with NAFLD could significantly improve serum transaminase activities independent of body weight (BW) changes. Some NAFLD patients could be associated with CIH due to OSA independent of BW changes. We propose that all NAFLD patients be analyzed by polysomnography for the diagnosis of OSA if any symptoms related to OSA become apparent.