RESEARCH ARTICLE Positive Effects of Voluntary Running on Metabolic Syndrome-Related Disorders in Non-Obese Hereditary Hypertriacylglycerolemic Rats

While metabolic syndrome is often associated with obesity, 25 % of humans suffering from it are not obese and the effect of physical activity remains unclear in such cases. Therefore, we used hereditary hypertriaclyglycerolemic (HHTg) rats as a unique model for studying the effect of spontaneous physical activity [voluntary running (VR)] on metabolic syndrome-related disorders, such as dyslipidemia, in non-obese subjects. Adult HHTg males were fed standard (CD) or high-sucrose (HSD) diets ad libitum for four weeks. Within both dietary groups, some of the rats had free access to a running wheel (CD+VR, HSD+VR), whereas the controls (CD, HSD) had no possibility of extra physical activity. At the end of the four weeks, we measured the effects of VR on various metabolic syndrome-associated parame-ters: (i) biochemical parameters, (ii) the content and composition of triacylglycerols (TAG), diacylglycerols (DAG), ceramides and membrane phospholipids, and (iii) substrate utiliza-tion in brown adipose tissue. In both dietary groups, VR led to various positive effects: re-duced epididymal and perirenal fat depots; increased epididymal adipose tissue lipolysis; decreased amounts of serum TAG, non-esterified fatty acids and insulin; a higher insuli