The effect of six-week high-intensity interval training on muscle expression of FTO and PPAR-γ in obese diabetic rats

Abstract

Background and purpose: Recent research suggests that obese people are up to 80 times more likely to develop type 2 diabetes than those with a normal BMI. Besides, obesity, inadequate physical activity, and unhealthy diets are the main causes of this metabolic disease. The purpose of this study was to investigate the effect of six weeks of high-intensity interval training on muscle expression of Fat mass and obesity-associated protein (FTO) and Peroxisome proliferator activator receptor gamma (PPAR-γ) in obese diabetic rats.
 Material and methods: This experimental study was carried out on 12 male Wistar rats (220±20 g bodyweight and 10 weeks old). Animals received a high-fat diet within six weeks, and then in order to induce type 2 diabetes, an intraperitoneal injection of a single dose of 30 mg/kg freshly prepared streptozotocin (STZ) (Sigma, USA) solved in citrate buffer (pH 4.5) was performed. Diabetic rats were divided into two (High-Intensity Interval Training and control) groups randomly. HIIT program included five sessions of 30 minutes per week. 48 hours after the last training session, the outcomes were measured. The muscle expression of FTO and PPAR-γ was measured using the real-time PCR method. Independent samples t-test and Analysis of covariance (ANCOVA) were applied to compare the means.
 Results: The expression of FTO (P<0.01), fasting blood sugar (P<0.001), weight (P<0.001) and HOMA-IR (P<0.004) significantly decreased after six weeks of high-intensity interval training, whilst PPAR-γ expression (P<0.007) significantly increased.
 Conclusion: Regarding the results of this study, it can be stated that a six-week HIIT program can improve glucose metabolism and insulin sensitivity. It can also increase the expression of diabetes- and obesity-associated genes (e.g., PPAR-γ and FTO), and thereby plays a prominent role in the control and treatment of type 2 diabetes in obese patients.

Effect of Exercise Training on Peroxisome Proliferator-Activated Receptor γ (PPAR-γ) Level: A Systematic Review

“…The remaining animal experiments confirmed an increase in PPAR-γ mRNA (28,(30)(31)(32)(33)(34)(35)(36)38) and PPAR-γ protein (37, 39) levels after exercise. A study on obese diabetic rats subjected to high-intensity interval training and a control group (5 sessions of 30 minutes per week) showed that the expression level of PPAR-γ 48 hours after the last training session was significantly increased (30). Motta et al also reported that high-intensity interval training led to significant reductions in body mass index (BMI) and FBG, improvements in the lipid profile, and an increase in PPAR-γ levels (32).…”

“…Among the 12 included animal studies, 11 papers (91%) demonstrated that various types of exercise and training programs, such as regular exercise, resistance exercise, swimming, climbing, and treadmill running, effectively improved PPAR-γ levels (28,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39). Only one study by Kawanishi et al reported that AE downregulated PPAR-γ expression in the liver and macrophages (29).…”

“…However, only one study showed that exercise training reduced the amount of macrophages in the liver and down-regulated PPAR-γ mRNA gene expression levels in the liver and macrophages in a non-alcoholic steatohepatitis model in mice (29). The remaining animal experiments confirmed an increase in PPAR-γ mRNA (28,(30)(31)(32)(33)(34)(35)(36)38) and PPAR-γ protein (37, 39) levels after exercise. A study on obese diabetic rats subjected to high-intensity interval training and a control group (5 sessions of 30 minutes per week) showed that the expression level of PPAR-γ 48 hours after the last training session was significantly increased (30).…”