Lecture Notes on Diabetes Mellitus

Overview

• Diabetes Mellitus involves issues with glucose transport from blood to cells, leading to high blood glucose levels.
• Two main hormones regulate blood glucose: Insulin (lowers) and Glucagon (raises).

Types of Diabetes

Type 1 Diabetes Mellitus

• Mechanism: Autoimmune attack on pancreatic beta cells, reducing insulin production.
• Genetic Factors: Linked with specific HLA genes (HLA-DR3, HLA-DR4).
• Symptoms: Polyphagia, glycosuria, polyuria, polydipsia.
• Complications: Diabetic Ketoacidosis (DKA) involving increased blood acidity, Kussmaul respirations, and hyperkalemia.
• Treatment: Lifelong insulin therapy.

Type 2 Diabetes Mellitus

• Mechanism: Insulin resistance in tissues; cells don't respond to insulin properly.
• Risk Factors: Obesity, inactivity, genetics.
• Beta Cell Response: Hyperplasia and hypertrophy lead to increased insulin production, but eventual exhaustion.
• Complications: Hyperosmolar Hyperglycemic State (HHS).
• Treatment: Lifestyle changes, oral medications, and insulin if necessary.

Other Types

• Gestational Diabetes: Occurs during pregnancy, related to insulin resistance.
• Drug-Induced Diabetes: Caused by medications increasing blood glucose levels.

Diagnosis

• Tests: Fasting glucose test, Non-fasting glucose test, Oral glucose tolerance test, HbA1c test, C-peptide test.
• Criteria: Specific glucose level thresholds for prediabetes and diabetes.

Complications of Diabetes

• Microvascular Damage:
  • Hyaline arteriolosclerosis in arterioles.
  • Capillary basement membrane thickening.
• Macrovascular Damage: Atherosclerosis leading to heart attacks and strokes.
• Retinopathy: Can cause blindness.
• Nephropathy: Leads to reduced kidney function and potential dialysis.
• Neuropathy: Decreased sensation, autonomic nervous dysfunction.
• Ulcers and Amputations: Poor healing, especially in feet.

Management and Prevention

• Focus on healthy lifestyle and controlling blood sugar levels to prevent complications.
• Type 1 cannot be prevented, but Type 2 can, and effective management allows for a full, active life.