title: Effects of acute hypoxia on human adipose tissue lipoprotein lipase activity and lipolysis.
abstract: Adipose tissue regulates postprandial lipid metabolism by storing dietary fat through lipoprotein lipase-mediated hydrolysis of exogenous triglycerides, and by inhibiting delivery of endogenous non-esterified fatty acid to nonadipose tissues. Animal studies show that acute hypoxia, a model of obstructive sleep apnea, reduces adipose tissue lipoprotein lipase activity and increases non-esterified fatty acid release, adversely affecting postprandial lipemia. These observations remain to be tested in humans.
  
  
  
  We used differentiated human preadipocytes exposed to acute hypoxia as well as adipose tissue biopsies obtained from 10 healthy men exposed for 6 h to either normoxia or intermittent hypoxia following an isocaloric high-fat meal.
  
  
  
  In differentiated preadipocytes, acute hypoxia induced a 6-fold reduction in lipoprotein lipase activity. In humans, the rise in postprandial triglyceride levels did not differ between normoxia and intermittent hypoxia. Non-esterified fatty acid levels were higher during intermittent hypoxia session. Intermittent hypoxia did not affect subcutaneous abdominal adipose tissue lipoprotein lipase activity. No differences were observed in lipolytic responses of isolated subcutaneous abdominal adipocytes between normoxia and intermittent hypoxia sessions.
  
  
  
  Acute hypoxia strongly inhibits lipoprotein lipase activity in differentiated human preadipocytes. Acute intermittent hypoxia increases circulating plasma non-esterified fatty acid in young healthy men, but does not seem to affect postprandial triglyceride levels, nor subcutaneous abdominal adipose tissue lipoprotein lipase activity and adipocyte lipolysis.
authors.affiliation: Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health, Sciences, University of Ottawa, 125, University Street (room 350), Ottawa, ON, K1N 6N5, Canada.
authors.forename: Bimit
authors.initials: B
authors.lastname: Mahat
authors.affiliation: Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health, Sciences, University of Ottawa, 125, University Street (room 350), Ottawa, ON, K1N 6N5, Canada.
authors.forename: Étienne
authors.initials: É
authors.lastname: Chassé
authors.affiliation: Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health, Sciences, University of Ottawa, 125, University Street (room 350), Ottawa, ON, K1N 6N5, Canada.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Mauger
authors.affiliation: Behavioral and Metabolic Research Unit, School of Human Kinetics, Faculty of Health, Sciences, University of Ottawa, 125, University Street (room 350), Ottawa, ON, K1N 6N5, Canada. imbeault@uottawa.ca.
authors.forename: Pascal
authors.initials: P
authors.lastname: Imbeault
mesh_terms: D017667:Adipocytes / Q000378:metabolism; D000273:Adipose Tissue / Q000201:enzymology* / Q000473:pathology*; D000328:Adult; D002454:Cell Differentiation; D005260:Female; D006339:Heart Rate; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000201:enzymology* / Q000473:pathology*; D008066:Lipolysis; D008071:Lipoprotein Lipase / Q000378:metabolism*; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins; C548261:LPL protein, human; D008071:Lipoprotein Lipase
keywords: Adipose tissue metabolism; Cardiovascular disease; Intermittent hypoxia; Obstructive sleep apnea; Postprandial lipemia