Insulin

Complete Guide with FAQs

Introduction

• Insulin is a hormone produced by the pancreas that regulates blood glucose levels by facilitating the uptake of glucose into cells.
• For individuals with diabetes, particularly type 1 diabetes and advanced type 2 diabetes, insulin therapy is essential to maintain blood sugar control and prevent complications.
• Modern insulin therapies are tailored to mimic natural insulin secretion, offering flexibility and precision in glucose management.

Types of Insulin

1. Rapid-Acting Insulin

• Examples: Aspart (Novolog), Lispro (Humalog), Glulisine (Apidra).
• Onset: 10–30 minutes.
• Peak: 30–90 minutes.
• Duration: 3–5 hours.
• Use: Taken before meals to control post-meal blood sugar spikes.

2. Short-Acting Insulin

• Examples: Regular insulin (Humulin R, Novolin R).
• Onset: 30–60 minutes.
• Peak: 2–4 hours.
• Duration: 5–8 hours.
• Use: Pre-meal dosing for glucose control.

3. Intermediate-Acting Insulin

• Examples: NPH insulin (Humulin N, Novolin N).
• Onset: 1–2 hours.
• Peak: 4–12 hours.
• Duration: 12–18 hours.
• Use: Covers insulin needs for about half a day or overnight.

4. Long-Acting Insulin

• Examples: Glargine (Lantus, Toujeo), Detemir (Levemir).
• Onset: 1–2 hours.
• Peak: Minimal or no peak.
• Duration: Up to 24 hours.
• Use: Provides basal insulin coverage throughout the day and night.

5. Ultra-Long-Acting Insulin

• Examples: Degludec (Tresiba).
• Onset: 1 hour.
• Peak: None.
• Duration: Over 42 hours.
• Use: Basal insulin with extended flexibility in dosing.

6. Premixed Insulin

• Examples: Humalog Mix 75/25, Novolog Mix 70/30.
• Components: Combination of intermediate-acting and rapid- or short-acting insulin.
• Use: Simplifies dosing for those who prefer fewer injections.

Indications for Insulin Therapy

• Type 1 diabetes: Essential for survival.
• Type 2 diabetes: Used when oral medications and lifestyle modifications fail.
• Gestational diabetes: For pregnant women with uncontrolled blood sugar.
• Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS).
• Temporary use in hospitalized patients or those with severe hyperglycemia.

How to Administer Insulin

Delivery Methods

• Syringes: Traditional method for insulin injections.
• Insulin Pens: Prefilled or refillable devices for ease of use.
• Insulin Pumps: Continuous subcutaneous insulin infusion with customizable basal and bolus doses.
• Inhalable Insulin: Rapid-acting insulin in powder form (e.g., Afrezza).

Injection Sites

• Abdomen, thighs, upper arms, and buttocks.
• Rotate sites to prevent lipodystrophy (fat deposits or breakdown).

Monitoring and Adjustments

• Regular blood glucose monitoring is essential.
• Adjust doses based on blood sugar levels, meal patterns, physical activity, and illness.
• Use of continuous glucose monitors (CGMs) can improve glucose control and reduce hypoglycemia.

Side Effects

Common Side Effects

• Hypoglycemia (low blood sugar).
• Weight gain.
• Injection site reactions, such as redness or swelling.

Rare but Serious Side Effects

• Severe hypoglycemia leading to confusion, seizures, or loss of consciousness.
• Allergic reactions to insulin or preservatives.
• Lipodystrophy from repeated injections at the same site.

Patient Counseling Points

• Take insulin as prescribed and never skip doses without consulting your doctor.
• Learn to recognize and manage hypoglycemia symptoms (e.g., shakiness, sweating, confusion).
• Keep a consistent eating schedule and match insulin doses to carbohydrate intake.
• Always carry a source of fast-acting glucose (e.g., glucose tablets, juice).
• Store insulin properly: unopened vials/pens in the refrigerator; opened ones can be kept at room temperature for a limited time (check manufacturer’s instructions).

Use in Children

• Insulin pumps are often preferred for children due to flexibility.
• Education for caregivers and school staff is critical to prevent and manage hypoglycemia.

Use in Pregnancy

• Insulin is the safest option for managing blood sugar during pregnancy.
• Long-acting insulins like detemir or glargine may be used under supervision.

Use in Elderly

• Simplified regimens are often preferred to reduce hypoglycemia risk.
• Regular monitoring of kidney function is necessary to adjust doses appropriately.

FAQs About Insulin

Q1: What is insulin, and why is it important?

• Insulin is a hormone that helps regulate blood sugar by allowing glucose to enter cells.

Q2: How does insulin therapy work?

• It replaces or supplements the body’s insulin to control blood sugar levels.

Q3: Can insulin cure diabetes?

• No, insulin manages diabetes but does not cure it.

Q4: What is the difference between rapid-acting and long-acting insulin?

• Rapid-acting insulin works quickly to control blood sugar after meals, while long-acting insulin provides steady coverage throughout the day.

Q5: How do I store insulin?

• Unopened insulin should be refrigerated. Opened insulin can usually be stored at room temperature for up to 28 days.

Q6: Can insulin cause weight gain?

• Yes, insulin can lead to weight gain, especially if calorie intake is not balanced.

Q7: How do I manage insulin-induced hypoglycemia?

• Treat with 15–20 grams of fast-acting carbohydrates like juice or glucose tablets.

Q8: Can insulin be taken orally?

• No, insulin is not effective when taken orally because it is broken down in the digestive system.

Q9: How often should I check my blood sugar on insulin?

• Frequency depends on the regimen but typically includes before meals, after meals, and at bedtime.

Q10: What is the role of insulin pumps?

• Insulin pumps provide continuous insulin delivery and greater flexibility in managing blood sugar.

Q11: Are there alternatives to insulin for type 2 diabetes?

• Yes, oral medications and non-insulin injectables, but insulin may be necessary as the disease progresses.

Q12: Can I exercise while on insulin?

• Yes, but monitor blood sugar closely as exercise can lower glucose levels.

Q13: Can insulin cause allergic reactions?

• Rarely, but reactions like swelling, redness, or rash at the injection site can occur.

Q14: What happens if I miss an insulin dose?

• Take it as soon as you remember unless it’s close to the next dose. Consult your doctor for advice.

Q15: Is insulin safe for long-term use?

• Yes, when used as prescribed, it effectively manages diabetes over the long term