Insulin therapy plays a crucial role in managing type 1 diabetes.

Proper glycemic control helps avoid the immediate dangers of high and low blood sugar levels and lowers the risk of long-term complications.

Primary care providers can assist individuals with type 1 diabetes by gaining a clear understanding of their insulin regimen, ensuring the treatment plan is well-optimized, and addressing any challenges related to adherence.

Insulin: A Lifeline for People with Type 1 Diabetes

Type 1 diabetes occurs due to the loss of pancreatic beta cells, resulting in insulin deficiency. Without insulin, hyperglycemia can lead to diabetic ketoacidosis, a potentially fatal condition. Insulin therapy is typically initiated in secondary care or an outpatient diabetes clinic.

The goal of an insulin regimen is to mimic natural insulin production to prevent hyperglycemia. Achieving effective diabetes control, both in the short and long term, requires an insulin regimen tailored to the individual's needs.

Insulin Regimens

There are three primary types of insulin regimens used by individuals with diabetes: basal-bolus, biphasic, and continuous subcutaneous infusion. Basal-bolus and continuous subcutaneous infusion regimens are commonly used for people with type 1 diabetes, while biphasic regime

Basal-Bolus Regimens: This approach combines short-acting insulin, which is taken before or with meals and snacks, and intermediate or long-acting (basal) insulin, which is typically injected once or twice daily. Several types of short-acting and basal insulins are available and fully subsidized. Basal-bolus regimens are usually flexible, allowing doses to be adjusted according to the carbohydrate content of meals.

This flexibility provides more freedom in meal timing and food choices, reducing the risk of hypoglycemia if daily routines change. Fixed-dose regimens are an alternative for those who can't count carbohydrates, but they require careful management of carbohydrate intake throughout the day to avoid hypoglycemia.

Continuous Subcutaneous Infusion: This regimen uses a short-acting insulin delivered by a pump over a 24-hour period, providing a basal rate with additional boluses at mealtime. This method eliminates the need for intermediate or long-acting insulin and closely mimics natural insulin production. The basal rate is individualized to match the person’s varying insulin needs throughout the day.

Short-Acting Insulin

In New Zealand, four types of short-acting insulins are fully subsidized (see Table 1 for brand names and variations). Insulin aspart, insulin glulisine, and insulin lispro (rapid-acting insulin analogues) have a faster onset and shorter duration of action than human neutral insulin.

Studies suggest that these analogues may be associated with fewer hypoglycemic events and better post-meal blood glucose control. Rapid-acting insulin analogues can be used in insulin pumps, whereas human neutral insulin is not recommended for this purpose due to the risk of precipitation in the pump's catheter or needle.

Strategies to Minimize the Risk of Insulin Dosing Errors

1. Use the chosen insulin with the correct delivery device, such as a cartridge or disposable pen.

2. Choose both short-acting and basal insulin from the same manufacturer to ensure familiarity with the delivery system.

3. Ensure the needle length is suitable; most individuals with type 1 diabetes typically use 4 mm needles.

4. Always write out the word units in full to avoid confusion.

5. Prescribe insulin by its full brand name, and be cautious when prescribing or dispensing products with similar names, such as Humalog, Humalog Mix, and Humulin, or Novomix and Novorapid.

The Role of Insulin in the Human Body

Video by Mechanisms in Medicine