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Effects of Acute Hypoxia on Human Adipose Tissue Lipoprotein Lipase Activity and Lipolysis
Author(s) -
Mahat Bimit,
Chassé Étienne,
Mauger JeanFrançois,
Imbeault Pascal
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.758.6
Subject(s) - nefa , lipolysis , endocrinology , medicine , adipose tissue , lipoprotein lipase , postprandial , hypoxia (environmental) , intermittent hypoxia , triglyceride , adipocyte , chemistry , insulin , obstructive sleep apnea , cholesterol , organic chemistry , oxygen
Context Adipose tissue regulates postprandial lipid metabolism by storing dietary fat through lipoprotein lipase (LPL)‐mediated hydrolysis of dietary triglycerides, and by inhibiting non‐esterified fatty acid (NEFA) delivery to nonadipose tissues. Studies conducted in animal showed that acute intermittent hypoxia, a model of obstructive sleep apnea, reduce adipose tissue LPL activity and increase NEFA release, adversely affecting postprandial lipemia. These observations remain to be tested in humans. Objective To investigate the effects of acute hypoxia on human adipose tissue LPL activity and lipolysis. Methods Differentiated human preadipocytes were exposed to hypoxia (3% O 2 ) for 24h and adipose tissue biopsies were obtained from 10 healthy men exposed for 6 hours to either normoxia or intermittent hypoxia following an isocaloric high‐fat meal. Results In differentiated human preadipocytes, acute hypoxia induced a 6‐fold reduction in LPL activity (p<0.001). In humans, the rise in postprandial triglyceride levels did not differ between normoxia and intermittent hypoxia. NEFA levels were significantly higher during intermittent hypoxia session (condition effect, p<0.05). Intermittent hypoxia did not affect subcutaneous abdominal adipose tissue LPL activity. No difference in lipolytic‐induced responses of isolated subcutaneous abdominal adipocytes were observed between normoxia and intermittent hypoxia sessions. Conclusions Acute hypoxia strongly inhibits LPL activity in differentiated subcutaneous abdominal preadipocytes. Acute intermittent hypoxia increases circulating plasma NEFA in young healthy men, but does not seem to affect postprandial triglyceride levels, nor subcutaneous abdominal adipose tissue LPL activity and adipocyte lipolysis. Support or Funding Information The study is dedicated to the memory of our colleague Michaël Babinsky. We are grateful to Mrs. Ann Beninato and Sabrina Ait‐Ouali for their technical assistance. Bimit Mahat is a recipient of a Ontario Graduate scholarship. Étienne Chassé is a recipient of a Institut de recherche de l'Hôpital Montfort scholarship. This study was supported by the Natural Sciences and Engineering Research Council of Canada as well as the University of Ottawa.