title: The effect of aerobic exercise on intrahepatocellular and intramyocellular lipids in healthy subjects.
abstract: BACKGROUND
  Intrahepatocellular (IHCL) and intramyocellular (IMCL) lipids are ectopic lipid stores. Aerobic exercise results in IMCL utilization in subjects over a broad range of exercise capacity. IMCL and IHCL have been related to impaired insulin action at the skeletal muscle and hepatic level, respectively. The acute effect of aerobic exercise on IHCL is unknown. Possible regulatory factors include exercise capacity, insulin sensitivity and fat availability subcutaneous and visceral fat mass).
  
  
  OBJECTIVE
  To concomitantly investigate the effect of aerobic exercise on IHCL and IMCL in healthy subjects, using Magnetic Resonance spectroscopy.
  
  
  METHODS
  Normal weight, healthy subjects were included. Visit 1 consisted of a determination of VO2max on a treadmill. Visit 2 comprised the assessment of hepatic and peripheral insulin sensitivity by a two-step hyperinsulinaemic euglycaemic clamp. At Visit 3, subcutaneous and visceral fat mass were assessed by whole body MRI, IHCL and IMCL before and after a 2-hours aerobic exercise (50% of VO(2max)) using ¹H-MR-spectroscopy.
  
  
  RESULTS
  Eighteen volunteers (12M, 6F) were enrolled in the study (age, 37.6±3.2 years, mean±SEM; VO(2max), 53.4±2.9 mL/kg/min). Two hours aerobic exercise resulted in a significant decrease in IMCL (-22.6±3.3, % from baseline) and increase in IHCL (+34.9±7.6, % from baseline). There was no significant correlation between the exercise-induced changes in IMCL and IHCL and exercise capacity, subcutaneous and visceral fat mass and hepatic or peripheral insulin sensitivity.
  
  
  CONCLUSIONS
  IMCL and IHCL are flexible ectopic lipid stores that are acutely influenced by physical exercise, albeit in different directions.
  
  
  BACKGROUND
  ClinicalTrial.gov NCT00491582.
authors: Division of Endocrinology, Diabetology and Clinical Nutrition, University Hospital of Bern, Inselspital, Bern, Switzerland.
authors: Andrea
authors: A
authors: Egger
authors: Roland
authors: R
authors: Kreis
authors: Sabin
authors: S
authors: Allemann
authors: Christoph
authors: C
authors: Stettler
authors: Peter
authors: P
authors: Diem
authors: Tania
authors: T
authors: Buehler
authors: Chris
authors: C
authors: Boesch
authors: Emanuel R
authors: ER
authors: Christ
mesh_terms: D000328:Adult; D015444:Exercise; D005080:Exercise Test; D005260:Female; D015309:Glucose Clamp Technique; D064368:Healthy Volunteers; D006801:Humans; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000166:cytology; D050356:Lipid Metabolism; D008099:Liver / Q000166:cytology*; D008297:Male; D018482:Muscle, Skeletal / Q000166:cytology*; D010100:Oxygen / Q000378:metabolism; D050151:Subcutaneous Fat / Q000166:cytology
chemical_list: D010100:Oxygen
references: J Am Coll Nutr. 2007 Aug;26(4):321-6
references: 17906183
references: Hepatology. 2004 Aug;40(2):386-93
references: 15368443
references: Endocrinol Metab Clin North Am. 2008 Dec;37(4):841-56
references: 19026935
references: Diabetes. 2012 Nov;61(11):2787-95
references: 22751691
references: J Clin Endocrinol Metab. 2003 Apr;88(4):1610-6
references: 12679446
references: Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):709-14
references: 20842026
references: Am J Physiol. 1979 Sep;237(3):E214-23
references: 382871
references: J Physiol. 2006 Jul 1;574(Pt 1):33-9
references: 16709637
references: Am J Physiol. 1990 Feb;258(2 Pt 1):E382-9
references: 2106269
references: Obesity (Silver Spring). 2009 Dec;17(12):2162-8
references: 19390517
references: Am J Physiol Endocrinol Metab. 2008 Jun;294(6):E1127-34
references: 18413676
references: J Physiol. 2003 Dec 1;553(Pt 2):611-25
references: 14514877
references: Eur J Appl Physiol. 2006 Nov;98(4):341-54
references: 16902796
references: NMR Biomed. 2006 Nov;19(7):968-88
references: 17075965
references: MAGMA. 2001 May;12(2-3):141-52
references: 11390270
references: J Magn Reson Imaging. 2012 Oct;36(4):951-60
references: 22645058
references: Ann Med. 2005;37(5):347-56
references: 16179270
references: Obes Res Clin Pract. 2011 Jul-Sep;5(3):e169-266
references: 24331107
references: Diabetes. 2000 May;49(5):677-83
references: 10905472
references: Eur J Appl Physiol Occup Physiol. 1988;57(5):554-7
references: 3396571
references: Int J Endocrinol. 2012;2012:983814
references: 22675355
references: Trends Endocrinol Metab. 2013 Jan;24(1):4-12
references: 23043895
references: J Clin Endocrinol Metab. 1991 Jan;72(1):96-107
references: 1986032
references: J Physiol. 2002 Sep 15;543(Pt 3):1033-46
references: 12231657
references: J Clin Endocrinol Metab. 2005 May;90(5):2804-9
references: 15741262
references: Essays Biochem. 2006;42:89-103
references: 17144882
references: NMR Biomed. 2010 Jun;23(5):532-8
references: 20213686
references: PLoS One. 2010 Oct 13;5(10):e13318
references: 20967198
references: Diabetologia. 2008 Aug;51(8):1457-65
references: 18512043
references: J Biol Chem. 2004 Jul 30;279(31):32345-53
references: 15166226
references: Acta Diabetol. 2000 Mar;37(1):47-53
references: 10928236
references: J Clin Invest. 2005 May;115(5):1343-51
references: 15864352
references: Proc Natl Acad Sci U S A. 2008 Oct 28;105(43):16701-6
references: 18936488
references: J Lipid Res. 2012 Mar;53(3):577-586
references: 22140269
references: J Appl Physiol (1985). 2003 Dec;95(6):2328-32
references: 12923116
references: Cardiovasc Diabetol. 2009 Aug 05;8:44
references: 19656356
references: J Physiol. 2002 Sep 15;543(Pt 3):1047-58
references: 12231658