Abstract

Background: Obesity is associated with many chronic disorders such as type-2 diabetes mellitus, essential hypertension and non-alcoholic fatty liver disease (NAFLD). High fat diet (HFD) induced obesity in rats is associated with altered adipocytes release of several adipocytokines. Physical exercise has also been shown to have positive effects in the prevention and attenuation of many of the obesity-related disorders, however; the mechanisms have not been fully elucidated.
Objective: The present study was designed to examine the effect of moderate intensity exercise training on existing cardio metabolic and hepatic complications linked to obesity including dyslipidemia, insulin resistance, hypertension and NAFLD.
Materials and methods: Thirty healthy adult male albino rats of initial body weight 151-190 gm were included. Rats were randomly and equally divided into 3 groups: group (1): normal diet fed group, group (II): HFD induced obesity group in which obesity was induced by HFD for 12 weeks and group (III): HFD induced obesity group fed on high fat diet for 12 weeks then followed by moderate intensity swimming exercise training for 8 weeks. Rats were examined for the body weight, length, abdominal circumference (AC) and body mass index (BMI), Systolic, diastolic & mean arterial blood pressures, heart rate, serum glucose, insulin & HOMA-IR, serum total cholesterol (TC), triglyceride (TG), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL) & atherogenic index (AI), serum adiponectin, leptin, irisin, , tumor necrosis factor alpha (TNF- α), Interleukin-6 (IL-6) malondialdehyde (MDA), superoxide dismutase (SOD), alanine aminotransferase (ALT), aspartate aminotransferase (AST), Alkaline Phosphatase (ALP), lactate dehydrogenase (LDH) and albumin. Histopathological examination for hepatic tissue was also evaluated.
Results: The present study revealed that HFD significantly increased final body weight, BMI, AC, Systolic, diastolic & mean arterial blood pressures, heart rate, serum levels of glucose, insulin, TC, TG, LDL, VLDL, ALT, AST, ALP, LDH, TNF- α, IL-6, MDA and leptin levels, in addition to HOMA-IR and atherogenic index in HFD-induced obesity group. However, there were significant decreases in serum levels of HDL, SOD, albumin, adiponectin and irisin levels in the same group. Histopathological changes in hepatic tissue that indicate the development of NASH were also observed in HFD-induced obesity group. On the other hand, chronic moderate intensity swimming exercise training significantly reversed all these manifestations even in the absence of caloric restriction.
Conclusion: moderate exercise training seems to be an effective strategy to reverse almost all risk factors of cardiovascular diseases and NAFLD associated with metabolic syndrome.

Keywords: Obesity; Oxidative stress; Non-alcoholic fatty liver disease; Hypertension