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World J Gastroenterol. Sep 14, 2010; 16(34): 4243-4252
Published online Sep 14, 2010. doi: 10.3748/wjg.v16.i34.4243
Obstructive sleep apnea syndrome and fatty liver: Association or causal link?
Mohamed H Ahmed, Christopher D Byrne
Mohamed H Ahmed, Chemical Pathology Department, Southampton University Hospital NHS Trust, Southampton, SO16 6YD, United Kingdom
Christopher D Byrne, Endocrinology and Metabolism, DOHaD Division, University of Southampton and Southampton University Hospitals Trust, Southampton, SO16 6YD, United Kingdom
Author contributions: Both authors contributed equally to this manuscript.
Correspondence to: Mohamed H Ahmed, MD, PhD, Chemical Pathology Department, Southampton University Hospital NHS Trust, Mail point 6-Level D, South Academic Block, Southampton, SO16 6YD, United Kingdom. elziber@yahoo.com
Telephone: +44-23-80798818 Fax: +44-23-80795255
Received: April 30, 2010
Revised: June 1, 2010
Accepted: June 8, 2010
Published online: September 14, 2010

Obstructive sleep apnea (OSA) is a complex disorder that consists of upper airway obstruction, chronic intermittent hypoxia and sleep fragmentation. OSA is well known to be associated with hypoxia, insulin resistance and glucose intolerance, and these factors can occur in the presence or absence of obesity and metabolic syndrome. Although it is well established that insulin resistance, glucose intolerance and obesity occur frequently with non-alcoholic fatty liver disease (NAFLD), it is now becoming apparent that hypoxia might also be important in the development of NAFLD, and it is recognized that there is increased risk of NAFLD with OSA. This review discusses the association between OSA, NAFLD and cardiovascular disease, and describes the potential role of hypoxia in the development of NAFLD with OSA.

Keywords: Sleep apnea syndrome, Hyperlipidemia, Non-alcoholic fatty liver disease, Insulin resistance