Insulin Types, Administration, and Oral Hypoglycemic Agents in Diabetes

Insulin Action Times

Understanding the action times of different insulin types is crucial for effective diabetes management. Here's a breakdown:

• Rapid-Acting:
  • Examples: Actrapid or Humulin Regular
  • Onset: 20-30 minutes
  • Peak: 2-4 hours
  • Duration: 6-8 hours
  • Note: Crystalline insulin
• Intermediate-Acting:
  • Examples: Insulatard or Humulin NPH
  • Onset: 45-60 minutes
  • Peak: 6 hours
  • Duration: 12-14 hours
  • Note: Protamine insulin
• Long-Acting:
  • Examples: Monotard or Slow
  • Onset: 60-90 minutes
  • Peak: 8-12 hours
  • Duration: 24 hours
  • Note: 70% zinc

When insulin is administered twice daily, typically 60% is given in the morning and 40% at night.

Managing Nocturnal Hypoglycemia

Nocturnal hypoglycemia with rebound hyperglycemia before breakfast (Somogyi effect) can be managed by checking capillary blood glucose around 3:00 AM.

Insulin Injection and Self-Injection

Insulin can be administered via intravenous bolus or continuous infusion in emergencies and severe hyperglycemia. However, the usual route is subcutaneous, preferably self-administered by the patient.

Body Map for Subcutaneous Insulin Injection

Anterior Body:

• Left arm: Divided into four zones
• Right arm: Divided into four zones
• Abdomen: Four zones on the outer edge of each side
• Thighs: Four zones on the outer edge and three on the inner side

Posterior Body:

• Arms: Three zones
• Buttocks: Four zones on the outer edge and three on the inner side

Injection Technique

• Insulin can be injected anywhere with subcutaneous tissue.
• Rotate injection sites, keeping injections 2 cm apart.
• Consider the varying absorption speeds in each zone.
• Hold the syringe vertically in obese individuals and at a 45-degree angle in normal-weight individuals.
• Pinching is not necessary if using a pen.
• Disinfecting the area is not necessary (insulin contains a sanitizer, and alcohol slows absorption due to vasoconstriction).
• Keep the needle in place for 10 seconds after injection to ensure the full dose is delivered.
• Avoid massaging the injection site afterward.

Factors Affecting Insulin Absorption

• Lipodystrophy Zones: Caused by repeated insulin action on subcutaneous adipose tissue.
• Anatomical Area: Increased absorption in the abdomen and thighs, minimal in the buttocks.
• Exercise: Increases blood flow, leading to faster absorption.
• Massage and Hot Baths/Showers: Increase blood flow, resulting in faster absorption.
• Dose: Larger volumes have slower absorption.
• Insulin Type: Rapid-acting insulins have faster absorption.

Oral Hypoglycemic Agents (OHAs)

General Indications for OHAs

• Onset of diabetes over 40 years old.
• Absence of ketosis or frank hyperglycemia.
• Low insulin requirements.
• Glycosylated hemoglobin between 6.5% and 7.5%.

General Contraindications for OHAs

• Ketosis and ketoacidosis.
• Liver and kidney insufficiency.
• Pregnancy and lactation.
• Frequent hyperglycemic episodes.
• Glycohemoglobin higher than 8.5%.

Treatment with Oral Hypoglycemic Agents in Type 2 Diabetes

In type 2 diabetes, there is a relative insulin deficiency coupled with tissue insulin resistance, often accompanied by overweight or obesity. Treatment aims to stimulate insulin secretion and improve insulin sensitivity.

Biguanides

• Do not stimulate the pancreas.
• Increase peripheral glucose uptake in muscles.
• Decrease intestinal glucose absorption.
• Inhibit gluconeogenesis.
• Often used in obese individuals with a reduced-calorie diet.
• Do not cause hypoglycemia.
• May have a mild appetite-suppressing effect.
• May cause mild, usually tolerable gastrointestinal effects.

Sulfonylureas

• Stimulate pancreatic insulin secretion.
• Inhibit intestinal mucosa secretion.
• Can cause hypoglycemia.
• Reduce glycated hemoglobin by 1-2%.
• When blood glucose is greater than 250, they indicate that insulin reserve exists.
• No effect in young individuals.
• Used in individuals with appropriate weight.