Effect of eicosapentaenoic acid ethyl ester v. oleic acid-rich safflower oil on insulin resistance in type 2 diabetic model rats with hypertriacylglycerolaemia.
The purpose of the present study was to test whether hyperlipidaemia and insulin resistance in type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats can be improved by dietary supplementation with purified eicosapentaenoic acid (EPA) or oleic acid (OA). Male OLETF rats were fed powdered chow (510 g fat/kg) alone (n 8) or chow supplemented with 10 g EPA- (n 8) or OA- (n 8) rich oil/kg per d from 5 weeks until 30 weeks of age. An oral glucose tolerance test and hyperinsulinaemic euglycaemic clamp was performed at 25 and 30 weeks of age. EPA supplementation resulted in significantly (P<0.05) reduced plasma lipids, hepatic triacylglycerols, and abdominal fat deposits, and more efficient in vivo glucose disposal compared with OA supplementation and no supplementation. OA supplementation was associated with significantly increased insulin response to oral glucose compared with EPA supplementation and no supplementation. Inverse correlation was noted between glucose uptake and plasma triacylglycerol levels (r -086, P<0.001) and abdominal fat volume (r -0.80, P<0.001). The result of oral glucose tolerance test study showed that the rats fed EPA tended to improve glucose intolerance, although this was not statistically significant. Levels of plasma insulin at 60 min after glucose was significantly increased in rats fed OA compared with the other two groups. The results indicate that long-term feeding of EPA might be effective in preventing insulin resistance in diabetes-prone rats, at least in part, due to improving hypertriacylglycerolaemia.
Minami
Asako
A
Department of Nutrition, School of Medicine, The University of Tokushima, Japan.
Ishimura
Noriko
N
Sakamoto
Sadaichi
S
Takishita
Eiko
E
Mawatari
Kazuaki
K
Okada
Kazuko
K
Nakaya
Yutaka
Y
D000005:Abdomen / Q000473:pathology; D000273:Adipose Tissue / Q000473:pathology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D019587:Dietary Supplements; D004195:Disease Models, Animal; D004435:Eating; D015118:Eicosapentaenoic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D015228:Hypertriglyceridemia / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D007333:Insulin Resistance; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D019301:Oleic Acid / Q000737:chemistry / Q000627:therapeutic use*; D051381:Rats; D020334:Rats, Inbred OLETF; D012450:Safflower Oil / Q000737:chemistry / Q000627:therapeutic use*; D014280:Triglycerides / Q000378:metabolism
D001786:Blood Glucose; D014280:Triglycerides; D019301:Oleic Acid; C035276:eicosapentaenoic acid ethyl ester; D012450:Safflower Oil; D015118:Eicosapentaenoic Acid