title: A potential link between endothelial function, cardiovascular risk, and metabolic syndrome in patients with Non-alcoholic fatty liver disease.
abstract: BACKGROUND
  Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide (NO) synthetase. Elevated ADMA reduces NO formation and is associated with endothelial dysfunction. The aims of this study were to evaluate endothelial function and the cardiovascular risk (CVR) profile in patients with non-alcoholic fatty liver disease (NAFLD), and to determine whether or not an association with metabolic syndrome (MS) increases these parameters.
  
  
  METHODS
  A total of 100 consecutive patients with NAFLD, who were seen in Liver Disease Outpatient clinic and 45 age- and sex-matched controls were included. Endothelial function was evaluated based on the serum ADMA level measured using a validated ELISA kit (DLD Diagnostika GMBH, Hamburg, Germany) and flow-mediated vasodilatation (FMV) measured via high-resolution external ultrasonography. The CVR profile was calculated according to the Framingham equation.
  
  
  RESULTS
  At baseline there weren't any significant differences in brachial artery diameter between the NAFLD and control groups (3.7 ± 0.6 mm vs. 3.6 ± 0.6 mm, respectively). FMV and flow-independent vasodilatation in response to sublingual nitroglycerin did not differ between the NAFLD and control groups (mean: 16% ± 9.4% vs. 17.9% ± 12.4%, and 21.4% ± 14% vs. 17.8% ± 11.3%, respectively, p > 0.05). No significant difference in the serum ADMA concentration between the NAFLD and control groups was observed (mean: 0.8 ± 0.07 μmol L(-1) vs. 0.74 ± 0.2 μmol L(-1), respectively). The CVR profile was significantly higher in the NAFLD group than in the control group (mean: 9% ± 6.9% vs. 4.6% ± 3.8%, P = 0.000). MS associated with NAFLD significantly increased the CVR profile (mean: 11.2% ± 7.4%, P = 0.000). An abnormal serum alanine aminotransferase level (>37 IU L(-1)) and the presence of fibrosis did not increase the CVR profile (p > 0.05).
  
  
  CONCLUSIONS
  The risk of cardiovascular events is increased in patients with NAFLD. The association with MS is further increased such risk.
authors.affiliation: Department of Internal Medicine, Ankara University, School of Medicine, Yeni Ziraat Mah. 656. sok. 22/4. Altındağ, Ankara, Turkey.
authors.forename: Muyesser
authors.initials: M
authors.lastname: Sayki Arslan
authors.affiliation: Department of Cardiology, Ankara University, School of Medicine, Ankara, Turkey.
authors.forename: Sibel
authors.initials: S
authors.lastname: Turhan
authors.affiliation: Department of Cardiology, Ankara University, School of Medicine, Ankara, Turkey.
authors.forename: Irem
authors.initials: I
authors.lastname: Dincer
authors.affiliation: Department of Internal Medicine, Ankara University, School of Medicine, Yeni Ziraat Mah. 656. sok. 22/4. Altındağ, Ankara, Turkey.
authors.forename: Dilsa
authors.initials: D
authors.lastname: Mizrak
authors.affiliation: Department of Endocrinology and Metabolism, Ankara University, School of Medicine, Ankara, Turkey.
authors.forename: Demet
authors.initials: D
authors.lastname: Corapcioglu
authors.affiliation: Department of Gastroenterology, Ankara University, School of Medicine, Ankara, Turkey.
authors.forename: Ramazan
authors.initials: R
authors.lastname: Idilman
keywords: Asymmetric dimethylarginine; Cardiovascular risk; Endothelial function; Metabolic syndrome; Non-alcoholic fatty liver disease