The objective of the study was to determine the effects of oxidized linoleic acid (Ox-LA) on plasma leptin and to determine the relationship between plasma leptin levels and atherosclerosis in animals treated with Ox-LA. Low-density lipoprotein (LDL) receptor knockout (LDL r−/−) mice were fed a high fat diet with or without Ox-LA for 11 weeks. Plasma leptin levels in the high fat group consuming Ox-LA were significantly higher (14,052 ± 601 pg/mL vs. 10,950 ± 541 pg/mL; P < .01) compared to the group receiving the high fat diet alone. There was a highly significant correlation between the plasma leptin levels and aortic atherosclerotic lesions. From this we conclude that chronic exposure to dietary Ox-LA increases the plasma levels of leptin in LDL r−/− mice on a high fat diet. Considering our previous finding that dietary Ox-LA increased atherosclerosis, the current findings emphasize the need to reduce dietary intake of oxidized fat.
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