Increase of Intrahepatocellular Lipids (IHCL) During Exercise in Healthy Volunteers

Chris Boesch¹, Andrea Egger², Roland Kreis¹, Michael Ith¹, Ina Krull², Jean-Marc Nuoffer³, Peter Diem², Christoph Stettler², Emanuel Christ²

Intramyocellular (IMCL) and intrahepatocellular lipids (IHCL) are both related to insulin sensitivity. This 1H-MR spectroscopy study investigates the influence of exercise on IHCL and IMCL levels in order to achieve an improved standardization of IHCL measurements and to understand the factors that increase IHCL levels. After exercise, IMCL is reduced, which contrasts to a significant increase of IHCL and of free fatty acids (FFA). The effect of increased IHCL may only partially be explained by a shrinking of hepatocites and a subsequent reduction of the water reference. It is concluded that the increased FFA levels stimulate the IHCL synthesis.