title: Polyunsaturated fatty acid pattern in liver and erythrocyte phospholipids from obese patients.
abstract: OBJECTIVE
  Our aim was to study the fatty acid (FA) composition of liver phospholipids and its relation to that in erythrocyte membranes from patients with obese nonalcoholic fatty liver disease (NAFLD), as an indication of lipid metabolism alterations leading to steatosis.
  
  
  METHODS
  Eight control subjects who underwent antireflux surgery and 12 obese patients with NAFLD who underwent subtotal gastrectomy with a gastro-jejunal anastomosis in Roux-en-Y were studied. The oxidative stress status of patients was assessed by serum F2-isoprostanes levels (gas chromatography/negative ion chemical ionization tandem mass spectrometry). Analysis of FA composition of liver and erythrocyte phospholipids was carried out by gas-liquid chromatography.
  
  
  RESULTS
  Patients with NAFLD showed serum F2-isoprostanes levels 84% higher than controls. Compared with controls, liver phospholipids from obese patients exhibited significantly 1) lower levels of 20:4n-6, 22:5n-3, 22:6n-3 [docosahexaenoic acid (DHA)], total long-chain polyunsaturated FA (LCPUFA), and total n-3 LCPUFA, 2) higher 22:5n-6 [docosapentaenoic acid (DPAn-6)] levels and n-6/n-3 LCPUFA ratios, and 3) comparable levels of n-6 LCPUFA. Levels of DHA and DPAn-6 in liver were positively correlated with those in erythrocytes (r = 0.77 and r = 0.90, respectively; p < 0.0001), whereas DHA and DPAn-6 showed a negative association in both tissues (r = -0.79, p < 0.0001 and r = -0.58, p < 0.01, respectively), associated with lower DHA/DPAn-6 ratios.
  
  
  CONCLUSIONS
  Obese patients with NAFLD showed marked alterations in the polyunsaturated fatty acid pattern of the liver. These changes are significantly correlated with those found in erythrocytes, thus suggesting that erythrocyte FA composition could be a reliable indicator of derangements in liver lipid metabolism in obese patients.
authors.affiliation: Department of Nutrition, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Elizondo
authors.forename: Julia
authors.initials: J
authors.lastname: Araya
authors.forename: Ramón
authors.initials: R
authors.lastname: Rodrigo
authors.forename: Jaime
authors.initials: J
authors.lastname: Poniachik
authors.forename: Attila
authors.initials: A
authors.lastname: Csendes
authors.forename: Fernando
authors.initials: F
authors.lastname: Maluenda
authors.forename: Juan C
authors.initials: JC
authors.lastname: Díaz
authors.forename: Cinzia
authors.initials: C
authors.lastname: Signorini
authors.forename: Cristiana
authors.initials: C
authors.lastname: Sgherri
authors.forename: Mario
authors.initials: M
authors.lastname: Comporti
authors.forename: Luis A
authors.initials: LA
authors.lastname: Videla
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism; D028441:F2-Isoprostanes / Q000032:analysis / Q000097:blood; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D005234:Fatty Liver / Q000209:etiology / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000378:metabolism*; D018384:Oxidative Stress; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism
chemical_list: D028441:F2-Isoprostanes; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids