Gut epithelial barrier markers in patients with obstructive sleep apnea

Sleep Med. 2016 Oct;26:12-15. doi: 10.1016/j.sleep.2016.01.019. Epub 2016 Sep 28.


Background: Obstructive sleep apnea (OSA) is now being recognized as an additional contributing factor to the pathogenesis of obesity-related comorbidities. At the same time, there is now increasing evidence to suggest that intestinal wall permeability plays a role in the development of metabolic syndrome. In the present study, circulating zonulin and fatty acid binding protein (I-FABP) were measured in association with metabolic, hepatic, and inflammatory parameters.

Results: Compared with controls, plasma I-FABP levels were significantly higher in patients with OSA (571 pg/mL [IQR 290-950] vs 396 pg/mL [IQR 234-559], p = 0.04). Zonulin levels were similar between groups. Significant relationships were observed between zonulin levels and waist circumference (p < 0.05), glucose (p < 0.05), and insulin (p < 0.05). In addition, in the OSA group, zonulin levels correlated negatively with the mean nocturnal oxygenation saturation (p < 0.05) and positively with total cholesterol (p < 0.05), alanine aminotransferase (ALT) (p < 0.005), aminotransferase (AST) (p < 0.01), gamma glutamyltransferase (GGT) (p < 0.005), and high-sensitivity C-reactive protein (hs-CRP) (p < 0.05). Multivariate analysis showed that associations between zonulin and ALT, AST, and hs-CRP were attenuated, but not eliminated, after adjustment for other variables.

Conclusions: The results of this study suggest that OSA is a risk factor for intestinal damage, regardless of metabolic profile, and that intestinal permeability might be a possible contributor to nonalcoholic fatty liver disease in patients with OSA.

Keywords: Fatty acid binding protein (I-FABP); Intestinal wall; Sleep apnea; Zonulin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alanine Transaminase / blood
  • Biomarkers / blood
  • Case-Control Studies
  • Cholera Toxin / blood*
  • Fatty Acid-Binding Proteins / blood*
  • Female
  • Humans
  • Intestinal Absorption / physiology*
  • Intestinal Mucosa / physiopathology
  • Male
  • Metabolic Syndrome / blood
  • Metabolic Syndrome / complications*
  • Middle Aged
  • Non-alcoholic Fatty Liver Disease / blood
  • Non-alcoholic Fatty Liver Disease / complications
  • Obesity / blood
  • Obesity / complications*
  • Retrospective Studies
  • Sleep Apnea, Obstructive / blood
  • Sleep Apnea, Obstructive / complications*
  • Sleep Apnea, Obstructive / physiopathology
  • Waist Circumference


  • Biomarkers
  • FABP1 protein, human
  • Fatty Acid-Binding Proteins
  • zonulin
  • Cholera Toxin
  • Alanine Transaminase