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Decreased Liver Fatty Acid Δ‐6 and Δ‐5 Desaturase Activity in Obese Patients
Author(s) -
Araya Julia,
Rodrigo Ramón,
Pettinelli Paulina,
Araya A. Verónica,
Poniachik Jaime,
Videla Luis A.
Publication year - 2010
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1038/oby.2009.379
Subject(s) - insulin resistance , medicine , steatosis , nonalcoholic fatty liver disease , endocrinology , fatty liver , polyunsaturated fatty acid , delta , oxidative stress , fatty acid , insulin , disease , chemistry , biochemistry , engineering , aerospace engineering
Steatosis in obese nonalcoholic fatty liver disease (NAFLD) patients is a clinicopathological condition associated with depletion of n‐3 polyunsaturated fatty acids (PUFA), a feature that may be related to PUFA desaturation. Liver Δ‐6 and Δ‐5 desaturase (Δ‐6D and Δ‐5D) activities, homeostasis model assessment of insulin resistance (HOMA IR ), and ferric reducing ability of plasma (FRAP) were evaluated in 13 obese patients who underwent subtotal gastrectomy with gastro‐jejunal anastomosis in Roux‐en‐Y and 15 nonobese patients who underwent laparoscopic cholecystectomy (controls). Liver Δ‐6D and Δ‐5D activities in obese patients were 87% and 66% lower than controls ( P < 0.001), respectively, with a 62% diminution in the Δ‐6D/Δ‐5D activity ratio ( P < 0.02). Δ‐6D inversely correlated with both HOMA IR ( r = −0.70, P < 0.0001) and oxidative stress assessed as the reciprocal value of FRAP ( r = −0.40, P < 0.05). Δ‐5D negatively correlated with HOMA IR ( r = −0.48, P < 0.01) but not with FRAP −1 ( r = −0.13, not significant). In conclusion, liver PUFA desaturation is diminished in obese NAFLD patients, in association with underlying insulin resistance and oxidative stress, which may play a role in altering lipid metabolism favoring fatty infiltration.