Summary of "Diabetes Mellitus | Clinical Medicine"

Main Ideas and Concepts

The video provides an extensive overview of Diabetes Mellitus, focusing on its pathophysiology, complications, diagnosis, and treatment strategies for both Type 1 and Type 2 Diabetes. It emphasizes the differences between the two types of diabetes, the complications arising from chronic hyperglycemia, and the management of hyperglycemic crises such as Diabetic Ketoacidosis (DKA) and Hyperglycemic Hyperosmolar Syndrome (HHS).

Key Points

Pathophysiology of Diabetes Mellitus

Type 1 Diabetes:
- Usually occurs in individuals under 30.
- Characterized by autoimmune destruction of pancreatic beta cells leading to insulin deficiency.
- Results in high blood glucose levels (hyperglycemia) due to inability to uptake glucose into cells.
- Associated with autoimmune diseases like celiac disease and Hashimoto's thyroiditis.
Type 2 Diabetes:
- More common in individuals over 40, though increasingly seen in younger populations.
- Often linked to metabolic syndrome, characterized by obesity and insulin resistance.
- Insulin receptors become less sensitive, leading to elevated blood glucose levels.
- Over time, beta cells may become exhausted and cease insulin production.

Common Symptoms and Complications

Classic symptoms: Polyuria, polydipsia, and polyphagia.
Hyperglycemia can lead to complications such as:
- DKA: More common in Type 1, involves ketone body formation due to fat breakdown, leading to metabolic acidosis.
- HHS: More common in Type 2, characterized by severe hyperglycemia without ketogenesis, leading to profound dehydration and altered mental status.

Diagnosis

Diagnostic tests include:
- Fasting plasma glucose ≥ 126 mg/dL.
- Random plasma glucose ≥ 200 mg/dL with symptoms.
- HbA1c ≥ 6.5%.
- Oral glucose tolerance test for gestational diabetes.
Differentiation between Type 1 and Type 2 can involve checking C-peptide levels and antibodies.

Treatment Strategies

Type 1 Diabetes:
- Insulin therapy is essential.
- Types of insulin:
  - Rapid-acting (e.g., Lispro) for meal coverage.
  - Long-acting (e.g., Glargine) for basal coverage.
Type 2 Diabetes:
- Lifestyle modifications (diet, exercise) are crucial.
- First-line medication: Metformin.
- If HbA1c remains high, consider adding second-line agents like GLP-1 agonists or SGLT2 inhibitors.
- Insulin may be required if multiple medications fail to control blood glucose.

Management of Hyperglycemic Crises

DKA Treatment:
- Rehydration with IV fluids (e.g., half-normal saline).
- Monitor and correct potassium levels before starting insulin.
- Use regular insulin infusion and adjust based on anion gap.
HHS Treatment:
- Similar rehydration approach.
- Insulin infusion to manage hyperglycemia, monitoring glucose levels closely.

Chronic Complications

Macrovascular complications: Increased risk of atherosclerosis, leading to strokes, myocardial infarctions, and peripheral artery disease.
Microvascular complications: Diabetic nephropathy and retinopathy.
Neuropathy: Can lead to diabetic foot ulcers and gastroparesis.