title: Apnoeic-hypopnoeic episodes during obstructive sleep apnoea are associated with histological nonalcoholic steatohepatitis.
abstract: BACKGROUND
  Nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnoea are associated with metabolic syndrome and atherosclerotic heart disease. This study evaluates the potential association between the NAFLD subtypes and a number of polysomnographical (PSG) parameters.
  
  
  METHODS
  This study included patients undergoing bariatric surgery with extensive clinical and histological data for whom complete PSG data before surgery were also available. Excess alcohol intake and other causes of liver disease were excluded. Apnoea, hypopnoea and apnoea-hypopnoea index (AHI) were calculated as described previously.
  
  
  RESULTS
  In this study, a total of 101 patients [77 nonalcoholic steatohepatitis (NASH) and 22 non-NASH controls] with PSG data were included (age 42.9 +/- 11.4 years, body mass index 51.6 +/- 9.5 kg/m(2), fasting serum glucose 117.4 +/- 53.4 mg/dl, fasting serum triglycerides 171.3 +/- 82.9 mg/dl, 58% hypertension and 33% diabetes mellitus). Subjects with histological NASH had significantly lower lowest desaturation (77 vs. 85%, P=0.006), lower mean nocturnal oxygen saturation (91 vs. 93%, P=0.05), higher AHI (35 vs. 22, P=0.03), higher respiratory disturbance index (46 vs. 21, P=0.02) and higher alanine aminotransferase/aspartate aminotransferase ratio (1.4 vs. 1.3, P=0.05) compared with non-NASH controls. In multivariate analysis, the lowest desaturation (P=0.04) was independently associated with histological NASH. Lowest desaturation and mean nocturnal oxygen saturation were significantly lower in subjects with fibrosis (76 vs. 85%, P=0.004 and 90.4 vs. 93.0%, P=0.02).
  
  
  CONCLUSIONS
  Our results suggest that the frequent nocturnal hypoxic episodes in NAFLD patients may be a risk factor for developing NASH. Additional studies are needed to study the effect of optimizing sleep apnoea management on the outcomes of patients with NAFLD.
authors.affiliation: Center for Liver Diseases, Inova Fairfax Hospital, Annandale, VA 22033, USA.
authors.forename: Poonam
authors.initials: P
authors.lastname: Mishra
authors.forename: Clarke
authors.initials: C
authors.lastname: Nugent
authors.forename: Arian
authors.initials: A
authors.lastname: Afendy
authors.forename: Chunhong
authors.initials: C
authors.lastname: Bai
authors.forename: Priya
authors.initials: P
authors.lastname: Bhatia
authors.forename: Mariam
authors.initials: M
authors.lastname: Afendy
authors.forename: Yun
authors.initials: Y
authors.lastname: Fang
authors.forename: Hazem
authors.initials: H
authors.lastname: Elariny
authors.forename: Zachary
authors.initials: Z
authors.lastname: Goodman
authors.forename: Zobair M
authors.initials: ZM
authors.lastname: Younossi
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D016022:Case-Control Studies; D045422:Continuous Positive Airway Pressure; D005234:Fatty Liver / Q000150:complications* / Q000473:pathology; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology; D008103:Liver Cirrhosis / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications / Q000601:surgery; D017286:Polysomnography; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology / Q000628:therapy