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Metabolic Implications of Dietary Trans ‐fatty Acids
Author(s) -
Dorfman Suzanne E.,
Laurent Didier,
Gounarides John S.,
Li Xue,
Mullarkey Tara L.,
Rocheford Erik C.,
SariSarraf Farid,
Hirsch Erica A.,
Hughes Thomas E.,
Commerford S. Renee
Publication year - 2009
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.2008.662
Subject(s) - medicine , endocrinology , insulin resistance , fatty acid , obesity , saturated fatty acid , diabetes mellitus , fatty liver , chemistry , trans fat , adipose tissue , elaidic acid , type 2 diabetes , biology , saturated fat , cholesterol , biochemistry , linoleic acid , disease
Dietary trans ‐fatty acids are associated with increased risk of cardiovascular disease and have been implicated in the incidence of obesity and type 2 diabetes mellitus (T2DM). It is established that high‐fat saturated diets, relative to low‐fat diets, induce adiposity and whole‐body insulin resistance. Here, we test the hypothesis that markers of an obese, prediabetic state (fatty liver, visceral fat accumulation, insulin resistance) are also worsened with provision of a low‐fat diet containing elaidic acid (18:1 t ), the predominant trans ‐fatty acid isomer found in the human food supply. Male 8‐week‐old Sprague–Dawley rats were fed a 10% trans ‐fatty acid enriched (LF‐ trans ) diet for 8 weeks. At baseline, 3 and 6 weeks, in vivo magnetic resonance spectroscopy ( 1 H‐MR) assessed intramyocellular lipid (IMCL) and intrahepatic lipid (IHL) content. Euglycemic–hyperinsulinemic clamps (week 8) determined whole‐body and tissue‐specific insulin sensitivity followed by high‐resolution ex vivo 1 H‐NMR to assess tissue biochemistry. Rats fed the LF‐ trans diet were in positive energy balance, largely explained by increased energy intake, and showed significantly increased visceral fat and liver lipid accumulation relative to the low‐fat control diet. Net glycogen synthesis was also increased in the LF‐ trans group. A reduction in glucose disposal, independent of IMCL accumulation was observed in rats fed the LF‐ trans diet, whereas in rats fed a 45% saturated fat (HF‐sat) diet, impaired glucose disposal corresponded to increased IMCL TA . Neither diet induced an increase in IMCL soleus . These findings imply that trans ‐fatty acids may alter nutrient handling in liver, adipose tissue, and skeletal muscle and that the mechanism by which trans ‐fatty acids induce insulin resistance differs from diets enriched with saturated fats.