Metabolic syndrome markers in wistar rats of different ages

Metabolic syndrome is characterized by a combination of risk factors for cardiovascular disease and diabetes that are generally linked to insulin resistance and central obesity [1]. Cardiovascular disease is the leading cause of morbidity and mortality in the world [2]; therefore, the study of metabolic syndrome as a predictor of cardiovascular problems is critical.Aging correlates with an increase in the prevalence of cardiovascular disease, which is a health concern, especially because of increases in the life expectancy of the world population. The aging of the world population has caused concerns about the balance of the age pyramid. Studies have estimated that the proportion of people over 65 years of age, which was 5.2 % in 1950, will increase to 15.6 % in 2050; thus, the elderly will represent one fifth of the world population [3].The prevalence of metabolic syndrome in the population of the United States is 20-25 % and close to 55 % for the elderly [4]. In Brazil, a metabolic syndrome prevalence of 52.3 % was observed in the elderly; however, due to different definitions for metabolic syndrome, the prevalence may differ among studies [3].The most commonly used definition for metabolic syndrome is the one given by the World Health Organization (WHO), which requires the presence of diabetes or insulin resistance and two of the following characteristics: a high waist/hip ratio, a high concentration of triglycerides or a low concentration of HDL cholesterol, increased blood pressure and urinary excretion of albumin [5].Research using animal models that develop a complete case of metabolic syndrome, including all of the above mentioned risk factors, are rare. Studies have demonstrated that the Wistar Ottawa Karlsburg (WOKW) line of rats develops a complete case of metabolic syndrome that includes obesity, moderate hypertension, dyslipidemia, glucose intolerance, and hyperinsulinemia [6].Another circumstance that leads to the manifestation of metabolic syndrome sy