Moderate- and High-Intensity Endurance Training Alleviate Diabetes-Induced Cardiac Dysfunction in Rats.

Area of Science:

• Cardiology
• Metabolic Diseases
• Exercise Physiology

Background:

• Type 2 diabetes (T2DM) is associated with adverse cardiac remodeling and dysfunction.
• The optimal exercise intensity for managing T2DM-related cardiac issues remains unclear.

Purpose of the Study:

• To investigate the effects of moderate-intensity training (MIT) and high-intensity interval training (HIIT) on cardiac dysfunction in a rat model of T2DM.
• To determine how exercise intensity influences cardiac remodeling and metabolic parameters in T2DM.

Main Methods:

• Rats with T2DM induced by a Western diet (WD) underwent 12 weeks of sedentary lifestyle, MIT, or HIIT.
• Cardiac function was assessed using echocardiography and hemodynamic measurements.
• Insulin resistance, glucose tolerance, plasma advanced glycation end-products (AGEs), cardiac fibrosis, and mitochondrial capacity were evaluated.

Main Results:

• Both MIT and HIIT improved insulin sensitivity and glucose tolerance compared to sedentary T2DM rats.
• MIT significantly reduced plasma AGE levels.
• Exercise interventions lowered cardiac end-diastolic pressure, left ventricular wall thickness, and interstitial collagen deposition.
• Cardiac citrate synthase activity, a marker of mitochondrial oxidative capacity, increased following both MIT and HIIT.

Conclusions:

• MIT and HIIT are effective in ameliorating diastolic dysfunction and pathological cardiac remodeling in T2DM.
• Exercise training improves cardiac outcomes in T2DM by reducing cardiac fibrosis and optimizing mitochondrial function.