Effects of Caloric Restriction on Blood Glucose and Serum Lipid Levels of OLETF Rats

To determine the effects of caloric restriction on obese type 2 diabetes we measured body blood glucose and serum lipid level in dietary restricted Otsuka Long Evans Tokushima Fatty (OLETF) rats. OLETF rats (obese diabetic rats) and Long Evans Tokushima Otsuka (LETO) rats (control rats) were grouped into 2 groups; control (free feed) group and 30% caloric restricted (30% CR) group. At 24 weeks of age the 30% CR animals were provided a diet at a level of 30% less food (by weight) than control rats consumed during the previous week. Blood glucose levels and serum triglyceride, total cholesterol, and high density lipoprotein (HDL)-cholesterol levels of CR rats were determined every 2 weeks for 8 weeks total. Blood glucose, triglyceride and total cholesterol levels of OLETF rats were significantly higher compared to LETO rats. In OLETF rats, the blood glucose levels were decreased to 61% by 8 weeks in the 30% CR compared to the non-CR control group, but changes of blood glucose levels were not observed in LETO rats during the 8weeks in the 30% CR. The serum triglyceride levels of OLETF rats were decreased significantly in the 30% CR but no change in the serum of LETO rats was found. The total cholesterol level was not changed by dietary restriction in LETO rats, but significant changes were observed in OLETF rats by 30% dietary restriction. HDL-cholesterol levels were also increased by dietary restriction in both LETO and OLETF rats. These results suggested that elevated blood glucose, triglyceride and total cholesterol levels in diabetes II patients may be reduced by caloric restriction.