Osmosis from Elsevier - Insulins ~Pharmacology~
Insulin is a peptide hormone produced by the pancreas that lowers blood glucose levels by facilitating glucose uptake into cells. It binds to insulin receptors, triggering glucose transport proteins to allow glucose entry into cells. Insulin promotes glycogenesis, glycolysis, lipogenesis, and protein synthesis while inhibiting glycogenolysis, gluconeogenesis, lipolysis, and proteolysis. In type 1 diabetes, the immune system attacks insulin-producing beta cells, reducing insulin production. Type 2 diabetes involves insulin resistance, leading to increased insulin demand and eventual beta cell atrophy. Insulin therapy, administered subcutaneously, is used to manage diabetes, with various types categorized by onset and duration: rapid, short, intermediate, long, and ultra-long acting. Rapid and short-acting insulins are used before meals, while longer-acting insulins maintain baseline glucose levels. Side effects include hypoglycemia, weight gain, and lipodystrophy. Insulin is crucial in managing diabetes during pregnancy and breastfeeding.
Key Points:
- Insulin facilitates glucose uptake into cells, lowering blood glucose levels.
- Type 1 diabetes involves immune destruction of insulin-producing cells; type 2 involves insulin resistance.
- Insulin therapy includes rapid, short, intermediate, long, and ultra-long acting types, tailored to patient needs.
- Side effects of insulin therapy include hypoglycemia, weight gain, and lipodystrophy.
- Insulin is essential for managing diabetes in pregnancy and breastfeeding.
Details:
1. 🔬 Insulin: Function and Mechanism
- Insulin, produced by pancreatic beta cells in the islets of Langerhans, plays a critical role in reducing blood glucose levels by promoting glucose uptake into muscle and adipose tissues.
- Insulin binds to receptors on cell membranes, triggering signaling pathways that include the activity of tyrosine kinase within the beta subunits of these receptors.
- The activation of these pathways leads to the integration of GLUT4 glucose transport proteins into the cell membrane, facilitating glucose entry and promoting glycogenesis, particularly in the liver and skeletal muscle.
- Insulin not only enhances glycogen storage but also stimulates glycolysis and lipogenesis when excess glucose is present.
- In skeletal muscles, insulin promotes amino acid uptake and protein synthesis, while also activating sodium-potassium ATPase pumps to lower extracellular potassium by shifting potassium into cells.
- By influencing these processes, insulin plays a crucial role in energy storage, metabolism, and maintaining electrolyte balance, highlighting its importance in overall physiological regulation.
2. 🩺 Diabetes Types: Causes and Effects
2.1. Causes of Type 1 Diabetes
2.2. Effects of Type 1 Diabetes
3. 💉 Insulin Therapy: Techniques and Administration
- Type 2 diabetes involves insulin resistance, causing increased insulin production demands on the pancreas and eventual beta-cell atrophy.
- Exogenous insulin is essential for type 1 and late-stage type 2 diabetes, administered subcutaneously due to gastrointestinal breakdown.
- Key insulin delivery methods include syringes, pens, and pumps, with abdominal injections offering the fastest absorption rates.
- Insulin types are classified by onset and duration: rapid, short, intermediate, long, and ultra-long acting, each serving different roles in glucose management.
- Rapid and short-acting insulins are primarily for bolus regimens to control postprandial glucose spikes.
- Intermediate, long, and ultra-long acting insulins are used in basal regimens to maintain consistent insulin levels.
- The basal-bolus regimen combines basal insulin for fasting glucose control and bolus insulin before meals for flexibility.
- Sliding scale insulin therapy, common in hospitals, requires frequent glucose monitoring and administration of short-acting insulin based on measured glucose levels.
- Insulin therapy is the preferred method for managing diabetes during pregnancy due to its efficacy and safety profile.
- Insulin pumps offer continuous insulin delivery, mimicking pancreatic function and providing improved control over blood glucose levels, especially beneficial for those with type 1 diabetes.
4. ⏳ Types of Insulin: Characteristics and Uses
4.1. Rapid-acting Insulins
4.2. Short-acting Insulins
4.3. Intermediate-acting Insulin - NPH
4.4. Long-acting Insulins
5. ⚠️ Insulin Therapy: Side Effects and Risks
- Insulin deud deck is an ultra-long-acting insulin formed by deleting a single amino acid from regular insulin.
- It is administered as a Depo injection, forming a heximer structure that slowly breaks down, with an onset action between 1 to 2 hours and lasting up to 48 hours.
- The main side effect of insulin therapy is hypoglycemia, particularly common with insulins that have a peak effect.
- Symptoms of hypoglycemia include headache, weakness, hunger, sweating, dizziness, anxiety, and tachycardia.
- Individuals with renal impairment, the elderly, and children younger than 7 are at higher risk of complications from insulin therapy.
- Managing hypoglycemia involves consuming fast-acting carbohydrates, such as glucose tablets or juice, and monitoring blood sugar levels regularly.
- Preventive measures include adjusting insulin doses, timing meals properly, and educating patients on symptom recognition.