Understanding Insulin

Most people associate diabetes with insulin, but the subject can be more complex than you think.

Insulin is available only as an injectable product. It’s understandable that many people who are started on insulin therapy have concerns and fears about injecting medications into their bodies. It is important that you have a thorough understanding of how to safely inject insulin and properly dispose of needles.

The first thing is to identify how often and how much insulin you will be using. It is therefore critical that you understand what type of insulin you will be using, and how each variety of insulin works.

For people with type 2 diabetes, some practitioners begin with a basal insulin at bedtime.^[1] By definition, basal insulin is a long-acting insulin product that releases small amounts of “background” insulin over time. These insulin products last from 24-72 hours. Remember, people with type 2 diabetes are generally producing some of their own insulin, and the dose of basal or background insulin they require is not a full therapeutic dose that a person with type 1 diabetes will need as insulin replacement.

The starting dose of basal insulin for someone with type 2 diabetes is often 10-20 units of a basal insulin given at bedtime.^[2] Some people may choose to give their injections in the morning. The main point to remember is that whatever time you decide to give your basal insulin injections, it should be at the same time of day every day. This is to keep insulin absorption as consistent as possible.^[3]

As previously mentioned, basal insulin is a background insulin that releases small amounts of insulin over time. It is a common misconception that you need to eat following a dose of any insulin. This is not the case with basal insulins such as glargine, degludec, and detimir. These insulin products last at least 24 hours and release insulin slowly throughout the day.

Another long-acting insulin is NPH insulin branded as NovolinN or Humulin N. This type of insulin is known as an intermediate-acting insulin, and lasts approximately 8-10 hours.  The intermediate insulin has a peak of about 6-8 hours after injecting, which under some circumstances covers lunch or mealtime.

The tricky thing about using this type of insulin is that you need to generally eat at the time of the peaking insulin, or risk having low blood sugar. NPH insulin is not clear and needs to be mixed or rolled (not shaken) before use. NPH insulin is also available in “pre-mixed” vials and pen devices. The pre-mixed insulin is usually given twice daily because NPH insulin is the shortest lasting basal insulin. This avoids needing separate bolus dosing for meals, but the insulin will have a peak effect after injecting of 4-8 hours depending on the individual, and food generally needs to be consumed at this peak to avoid low blood sugars.

Whether you’re living with type 1 or type 2 diabetes, if you’re using insulin it’s crucial to get a full understanding of what medication you need and how it’s affecting your body. Always speak with your healthcare team to fully understand what’s best for you and your health goals!