Comparison of high-fat and high-carbohydrate diets for obtaining an experimental model of metabolic syndrome

Abstract

Introduction. Metabolic syndrome is a cluster of metabolic abnormalities that includes hypertension, central obesity, insulin resistance and atherogenic dyslipidemia. Given the wide geographical distribution and growing number of people suffering from this disease, there is an urgent need in developing animal models that would accurately reproduce the development of all symptoms of human metabolic syndrome (insulin resistance, dyslipidemia, obesity and hypertension). The most cost-effective method related to the real causes of metabolic syndrome is the use of different types of diets. Materials and Methods. The study was performed on white outbred male rats about 6 months old and weighing 300–400 g. The metabolic syndrome was induced by high-fat and high-carbohydrate diets. The lipid-enriched diet involved the consumption of regular chow diet for laboratory animals with additional fat content (40 % by weight of chow). The source of additional lipids was olive oil, which is rich in monounsaturated fatty acids (MUFAs). Animals on the diet enriched in carbohydrates together with regular chow diet for laboratory animals consumed 10 % fructose solution instead of drinking water. Glucose tolerance tests were conducted and areas under the glycemic curves were calculated. We determined the content of glycated hemoglobin and glucose concent­ration, the concentration of low-density lipoproteins (LDL), high-density lipoproteins (HDL), triglycerides and cholesterol in the blood plasma of rats. Results. The development of metabolic syndrome induced by an excessive consumption of carbohydrates and lipids for 42 days was accompanied by impaired glucose tolerance, increased glycosylated hemoglobin, triglycerides and cholesterol concentrations, as well as a decreased HDL content. An increase in the concentrations of LDL and activity of paraoxonase were found due to the induction of the pathological condition by an excessive fat intake, while a high carbohydrate diet caused a decrease in paraoxonase activity. Conclusions. The use of fructose for 42 days causes the most pronounced manifestations of the studied pathology. The use of this model will allow determining the biochemical and molecular changes that accompany the development of this pathological condition. It will also facilitate the development and evaluation of the effectiveness of new therapeutic approaches to the treatment of metabolic syndrome.

Keywords

• metabolic syndrome
• diet-induced obesity models
• hyperglycemia
• dyslipidemia