Effects of fructose and/or fat in the diet on developing the type 2 diabetic-like syndrome in CD-1 mice

The aim of the present study was to examine the interactions of fructose and fat on glucose regulation and lipid metabolism in CD-1 mice. Mice were assigned in five groups. The control group was provided with tap water and a gavage of vehicle; four experimental groups were treated with 150 g/l fructose solution (FS1), fat emulsion (FE), 150 g/l fructose solution and fat emulsion (FS1+FE), or 70 g/l fructose solution and fat emulsion (FS2+FE) for 12 weeks. At the end of the 8th week, both oral glucose tolerance test and insulin tolerance test were conducted. Lipid profiles in serum, liver, and red gastrocnemius muscle, and serum insulin and glucose concentrations were assessed. The FS1+FE group showed combined glucose intolerance (CGI) and decrease of insulin sensitivity. The low-density lipoprotein cholesterol (LDL-C) concentrations were elevated in all experimental groups (p<0.05). The combined diet groups showed statistically significant (p<0.01) increase in total cholesterol (TC) level in comparison with the control FE (p<0.05), or FS1 (p<0.05) group. Triglyceride levels in liver and red gastrocnemius muscle were significantly increased in FE and combined groups. In conclusion, combination of FE and 150 g/l fructose solution for 8 weeks led to CGI. Fructose enhanced the adverse effect of FE on glucose regulation with increasing percentage in the diet. Furthermore, there was a synergistic effect of fructose and fat on elevating the serum TC level.