Insulin and Diabetes

What is Insulin?

Your healthcare team will develop a plan to help manage your diabetes. This will likely include changes to your eating plan, physical activity, and medications. Even if insulin is not a part of your care plan, it is important to understand its role, as diabetes is a progressive disease with ever-changing strategies for management.

Insulin is a hormone produced by the pancreas that keeps blood sugar within normal ranges in the bloodstream. Insulin moves the sugar (glucose) from the bloodstream into the cells to nourish the body. Everyone with type 1 diabetes requires insulin injections because their body produces little or no insulin. Some with type 1 diabetes go through a period referred to as a “honeymoon phase” shortly after diagnosis, where the pancreas may still produce a small amount of insulin. This phase can last weeks or months, but is temporary, resulting in the need for insulin injections. 

Types of Insulin

Insulin is classified based on how quickly it takes effect, when it has maximal effect and how long it last.

Categories

  • Rapid acting should be taken just before or just after eating.  It begins to lower blood glucose in less than 15 minutes. It continues to work for about 2 to 5 hours. Common rapid acting insulins include Insulin glulisine (ApidraÒ), insulin lispro (HumalogÒ), and insulin aspart (NovoLogÒ). FiaspÒ is a new rapid acting insulin aspart with a 2.5 minute onset.
  • Insulin human inhaled powder (AfrezzaÒ) mealtime insulin has a 3-7 minute onset and 1.5 to 3 hour duration.
  • Short acting should be taken 30 minutes before a meal.  It begins to lower blood glucose within 30 minutes to 1 hour. It lasts for about 5 to 8 hours. Common types are Humulin RÒ and Novolin RÒ.
  • Intermediate acting has an effect for 10-24 hours, depending on the type, so it is typically only taken once per day. Common types are NPH such as Humulin NÒ with a duration of 12-16 hours and Novolin NÒ with a duration up to 24 hours.
  • Long acting has an effect for 24 hours, depending on the type, so it is only taken once per day. This basal insulin has no peak. It is taken once per day. Common types include insulin detemir (LevemirÒ) and insulin glargine (LantusÒ) or (BasaglarÒ).
  • Ultra-long-acting is taken once a day. Insulin degludec (TrisebaÒ) has an onset of 1 hour and a duration of at least 42 hours. Insulin glarnine (ToujeoÒ) has an onset of 6 hours and duration of 36 hours.

Insulin can be packaged in vials, pens/cartridges, or inhaled. There are also pre-mixed insulins that contain a combination of insulin types described above. Hypoglycemia is a potential side effect of insulin. Education to prevent and treat hypoglycemia is necessary for individuals taking insulin.

Characteristics to consider with your insulin

  • Onset: how quickly it will start working
  • Peak: the time when the insulin is most effective in lowering blood glucose. Note that basal insulin has no peak so is always the same in terms of effectiveness.
  • Duration: how long it continues to have an effect on your blood glucose
  • Strength: the most common strength is U-100, which means it has 100 units of insulin per 1 milliliter of fluid. Insulin at U-500 and U-40 are available in some countries.
Common assumptions made about insulin that are not accurate 

I'm a failure if I have to take insulin. 

It is not uncommon for those with type 2 diabetes to eventually need insulin because diabetes is a progressive disease. Few people with type 2 diabetes start out taking insulin, but about one in three will end up taking insulin. The necessity for insulin injections should never be viewed as a failure. 

Taking insulin means my diabetes is somehow more serious. 

Insulin is a natural way to keep your diabetes well managed and prevent diabetes-related complications. It is most important to manage diabetes with the best medical therapy available. 

Insulin injections are painful. 

Most of us do not relish the thought of having to take daily injections. Insulin is injected into the fat right beneath the skin where there are few nerve endings. The pen needles and insulin syringes of today are so thin that most people report little to no discomfort. 

I will never be able to give myself a shot. 

Young and old alike can be taught how to administer an insulin injection. Special adaptive devices are available for those with poor dexterity, vision issues, or fear of needles. 

I will gain weight on insulin. 

Taking insulin can make weight loss more difficult, although decreasing caloric intake and increasing physical activity play the greatest role in weight status. If you do gain weight, talk to your dietitian and health care provider about making sure the meal plan and insulin plan are the best for you. 

If I agree to start insulin, it will be forever. 

Anyone with type 1 diabetes will have to take insulin forever. For others, it depends on how long you have had diabetes and how much insulin your pancreas is able to secrete. Many with type 2 diabetes can reduce or eliminate the need for insulin with the adoption of healthy lifestyle behaviors, like weight loss and increased physical activity. Newly developed diabetes medications can sometimes replace insulin. 

Insulin will cause low blood sugar. 

Low blood sugar (hypoglycemia) can happen with insulin; however, careful dosing, monitoring, and meal planning make hypoglycemia less common. The use of long-acting insulins has lessened hypoglycemia occurrences because these insulins do not peak like regular and fast-acting insulin.