Serum metabolomic profiling highlights pathways associated with liver fat content in a general population sample.

Authors:
M Koch, S Freitag-Wolf, S Schlesinger, J Borggrefe, J R Hov, M K Jensen, J Pick, M R P Markus, T Höpfner, G Jacobs, S Siegert, A Artati, G Kastenmüller, W Römisch-Margl, J Adamski, T Illig, M Nothnagel, T H Karlsen, S Schreiber, A Franke, M Krawczak, U Nöthlings, W Lieb
Year of publication:
2017
Volume:
-
Issue:
-
Issn:
0954-3007
Journal title abbreviated:
EUR J CLIN NUTR
Journal title long:
European journal of clinical nutrition
Impact factor:
2.935
Abstract: 
Fatty liver disease (FLD) is an important intermediate trait along the cardiometabolic disease spectrum and strongly associates with type 2 diabetes. Knowledge of biological pathways implicated in FLD is limited. An untargeted metabolomic approach might unravel novel pathways related to FLD.In a population-based sample (n=555) from Northern Germany, liver fat content was quantified as liver signal intensity using magnetic resonance imaging. Serum metabolites were determined using a non-targeted approach. Partial least squares regression was applied to derive a metabolomic score, explaining variation in serum metabolites and liver signal intensity. Associations of the metabolomic score with liver signal intensity and FLD were investigated in multivariable-adjusted robust linear and logistic regression models, respectively. Metabolites with a variable importance in the projection >1 were entered in in silico overrepresentation and pathway analyses.In univariate analysis, the metabolomics score explained 23.9% variation in liver signal intensity. A 1-unit increment in the metabolomic score was positively associated with FLD (n=219; odds ratio: 1.36; 95% confidence interval: 1.27-1.45) adjusting for age, sex, education, smoking and physical activity. A simplified score based on the 15 metabolites with highest variable importance in the projection statistic showed similar associations. Overrepresentation and pathway analyses highlighted branched-chain amino acids and derived gamma-glutamyl dipeptides as significant correlates of FLD.A serum metabolomic profile was associated with FLD and liver fat content. We identified a simplified metabolomics score, which should be evaluated in prospective studies.European Journal of Clinical Nutrition advance online publication, 5 April 2017; doi:10.1038/ejcn.2017.43.