Module 3: Cardiovascular Exercise & Diabetes

Module 3: Cardiovascular Exercise Principles - Week 3

• Module covers cardiovascular exercise principles and focuses on exercise prescription for diabetes.
• Learning objectives include defining diabetes, identifying physiological processes, treatment goals, potential complications, and designing effective exercise strategies.
• Diabetes is a chronic metabolic disease characterized by hyperglycemia.
• Types include type 1 (autoimmune, beta cell destruction) and type 2 (insulin resistance, defective insulin secretion). Gestational diabetes develops during pregnancy.

Exercise Prescription for Common Chronic Conditions - Diabetes

• The module addresses exercise prescription for individuals with diabetes.
• Learning objectives include defining diabetes, understanding the role of exercise in managing diabetes, the complications associated with exercise in diabetics, and strategies for managing type 2 diabetes through exercise.
• Blood glucose control is impaired in Type 2 diabetes.
• 24-hour blood glucose control in diabetics was studied by Van Dijk et al. in Diabetes Journal 2015. The study investigated this topic, covering various aspects of diabetes.
• The 2010 prevalence of diabetes among 20- to 79-year-olds in Europe, North America, and Oceania was examined.

Learning Objectives

• Define diabetes and its types
• Explain the physiological processes involved in blood glucose regulation and factors influencing high glucose levels in type 2 diabetes
• State the treatment goal for diabetes and the role of exercise in managing it, both acutely and chronically
• Discuss the complications associated with exercise in diabetics
• Design exercise strategies for managing type 2 diabetes

Overview of Glucose Transport in Skeletal Muscle

• Glucose transport into skeletal muscle can be insulin-stimulated or exercise-stimulated.
• Elevated circulating glucose triggers insulin release.
• Insulin interacts with receptors on target tissues, including skeletal muscle.
• Skeletal muscle accounts for 50-80% of insulin-stimulated glucose uptake. 
• Insulin movement to the skeletal muscle membrane facilitates glucose transport.

Pathophysiology of Insulin Resistance

• Adipose tissue (AT) can become insulin-resistant before skeletal muscle.
• Insulin resistance in AT leads to an increase in circulating lipids, affecting skeletal muscle function and impacting insulin signaling.
• Lipid accumulation and reactive lipid production result in impaired insulin signaling. This was further explored.
• This issue was explored in detail, focusing on how excess lipids impair insulin signaling, leading to resistance and hyperglycemia

Diabetic Complications

• Acute complications stemming from uncontrolled glucose levels include hyperglycemia, hypoglycemia, diabetic ketoacidosis, and hyperglycemic hyperosmolar nonketotic syndrome.
• Chronic complications such as peripheral neuropathies (somatic and autonomic), nephropathies, retinopathies, macro/microvascular complications, diabetic foot ulcers, and infections arise with long-term poor management.

Treatment Goals for Diabetes

• A combination of diet, medication, and regular exercise form the foundation for diabetes management.
• Dietary adjustments are crucial for blood glucose control.
• Medication use, including insulin and oral glucose-lowering agents, is essential for managing blood sugar levels.
• Regular exercise is a key component for enhancing both insulin and exercise-stimulated glucose transport.

Exercise-Stimulated Glucose Transport

• Exercise facilitates GLUT-4 translocation to the plasma membrane, thereby enhancing glucose transport independent of insulin.
• Exercise minimizes the formation of reactive lipids and increases lipid storage.
• The metabolic environment activated by exercise triggers GLUT-4 movement from intracellular locations to the plasma membrane.
• Exercise-induced metabolic environment enables enhanced glucose utilization within skeletal muscle.

Benefits of Chronic Exercise Training in Diabetes

• Chronic aerobic and resistance training directly improves insulin action and blood glucose control.
• Indirectly improves cardiovascular and metabolic fitness, thereby reducing risk factors such as obesity, hypertension, and high cholesterol for diabetes development/progression.

Prevalence and Diagnosis

• Prevalence of diagnosed diabetes among individuals aged one year and older, by age group and sex, Canada 2014/15.
• Prevalence trends and global figures on diabetes, particularly among 20 to 79-year-olds in Europe, North America, and Oceania (2010 data).
• Data sources, authors, and reference material provide contextual backing for these statistics, adding depth to the topic's background and current situation.

Exercise Prescription in Diabetes

• Individualized exercise prescription tailored to the presence of diabetic complications, and to the patient's individual medication regimen.
• Recommendations vary depending on the severity of diabetic complications and the patient's condition.
• Glucose control is a key goal.

Diabetic Complications, Diagnostic Criteria, and Common Medications

• Module details common medications for diabetes management, including oral anti-hyperglycemics and insulin.
• The module addresses the potential complications related to the medications, including factors contributing to high blood glucose levels in type 2 diabetes.
• Comprehensive overview and guidelines on various aspects of diabetes management, including diagnosis, criteria, and common medications used in the treatment process

Additional Information

• Acute exercise-induced blood glucose reduction in diabetic patients was shown to be significant.
• Exercise-induced movement of GLUT-4 to the plasma membrane is intact in diabetes.
• Understanding hormonal compensations and potential issues related to exercise regimens in those with diabetes is paramount.
• Factors such as insulin intake, medications, and carbohydrate consumption are essential considerations during exercise programs for diabetics.

Diagnostic Criteria and Exercise Testing guidelines

• The guidelines for exercise testing, provided in this module, are crucial considering that silent ischemia is often undetected.
• The information is pivotal to ensure responsible management practices when dealing with pre-existing conditions like diabetes.