Overview of Diabetes Mellitus

• A condition characterized by impaired insulin effects or receptor tissue response.
• Results in cell starvation for glucose, leading to decreased cellular function and ATP energy production.

Causes of Diabetes Mellitus

Type 1 Diabetes

• Autoimmune destruction of pancreatic beta cells in the islets of Langerhans.
• Leads to severe insulin deficiency.
• Cells cannot uptake glucose, causing persistent high blood glucose levels (hyperglycemia).

Type 2 Diabetes

• Insulin resistance:
  • The receptors on tissues do not respond properly to insulin.
  • Despite normal or high levels of insulin, glucose uptake by cells is impaired.
• Results in cell starvation, similar to type 1.

Effects of Insulin Deficiency or Resistance

• Glucose uptake into cells is hindered.
• Cells are starved for glucose, impacting ATP production.
• Cells switch to alternative energy sources:
  • Fat breakdown (lipolysis) producing fatty acids and ketones.
  • Protein breakdown for gluconeogenesis (glucose production).

Critical Tissues & Glucose Uptake by Different Cell Types

• Cell Types that always accept glucose without insulin:
  • Brain, kidneys, heart, intestinal cells, and exercising skeletal muscle.
• Implications:
  • These tissues remain functional in glucose uptake.
  • Others depend on insulin for glucose entry.

Clinical Implications of Diabetes Mellitus

• High blood glucose damages blood vessels, promoting atherosclerosis.
• Blood glucose range: 70-110 mg/dL for healthy regulation.
• Monitoring essential, especially during exercise.

Exercise and Blood Glucose Control

• Exercise improves glucose regulation.
• Specifically, exercise increases glucose uptake in skeletal muscles with less insulin.
• Helps prevent hyperglycemia and vascular damage.

Risks of Exercise

• Hypoglycemia if blood glucose drops too low during activity.
• Therefore, monitoring blood glucose levels is important during exercise.
• Symptoms of hypoglycemia: Dizziness, weakness, confusion, and in severe cases, coma.

Pathophysiological Effects of Uncontrolled Diabetes

• Elevated blood glucose damages blood vessels (macrovascular and microvascular disease).
• Increased risk of cardiovascular disease, retinal damage, stroke, and kidney failure.

Summary

• Maintaining blood glucose within normal limits is crucial.
• Both insulin deficiency (Type 1 Diabetes) and receptor resistance (Type 2 Diabetes) disrupt homeostasis.
• Lifestyle modifications like exercise and dietary management are key to control.
• Monitoring blood glucose levels regularly helps prevent complications.