Insulin Pump Therapy for Adults With Type 1 Diabetes

Written by Hope Warshaw, MMSc, RD, CDE, BC-ADM, FADCES

Everyone who has type 1 diabetes must take insulin to replace the insulin their body no longer makes in sufficient amounts. Today there are several different types of insulin, from short (also called rapid)-acting insulin to long-acting insulin. For the most part people with type 1 diabetes either take several injections of insulin each day (called multiple daily injection therapy [MDI]), using short- and long-acting insulin, or they use an insulin pump to deliver the insulin they need. Typically people who use insulin pump therapy use just one type of insulin and that’s short-acting.

There is no doubt, having to take insulin day in and day out to manage type 1 diabetes is burdensome. Use of insulin pump therapy to deliver insulin can make the ins and outs of taking insulin easier and more convenient. This article aims to help people with type 1 diabetes and their caregivers learn the basics about insulin pump therapy and determine if it is right for you or a loved one.

What are the basics of insulin pump therapy for type 1 diabetes?

An insulin pump delivers insulin, just like an injection, right under the skin (known as subcutaneously). But what is very different is that the insulin pump user gets their insulin continuously all day long. The insulin is delivered through a very narrow tube that is placed by the user with a thin short needle just under the skin. Also different is that insulin pump therapy uses just one type of insulin (short-acting). The pump delivers insulin as it is directed by the user’s settings in two ways – basal and bolus.¹ Note that user settings are prescribed and guided by the person’s diabetes healthcare providers.

What do the terms basal and bolus mean with regard to insulin delivery?

Basal Insulin

Think of basal insulin as the insulin that the pump user delivers in small amounts every few minutes throughout the day.² Basal insulin is the insulin a person needs to keep glucose levels within their target zone regardless of the food they eat. The basal insulin dose or doses once set in the pump are automatically delivered. However, they can be changed as needed. A big benefit of insulin pump therapy is that the user can determine their basal insulin needs and can set various rates for different time segments of the day or for different times when they need more or less insulin, such as menstrual cycle or the use of a medication that increases glucose levels. Other big benefits with regard to basal insulin in an insulin pump is that the user can temporarily set their basal rate to deliver more or less insulin for a period of time. This comes in handy for exercise, sick days and other situations.

Bolus Insulin

Think of bolus insulin doses as the insulin that the pump user, based on several factors agreed upon with their healthcare provider, chooses to take to manage (cover) the rise of glucose after eating.² Bolus insulin doses are also given or taken if and when there is a need to lower a higher than desirable glucose level. Here is another big benefit of insulin pump therapy with regard to bolus doses: depending on the functionalities of the pump, the user can choose to take the bolus dose all at once or extend all or part of it over a chosen number of hours.

When can a person with type 1 diabetes start insulin pump therapy?

A person with type 1 diabetes can successfully start insulin pump therapy at any point of their life with diabetes, including at the time of diagnosis.1 If insulin pump therapy is something that you and/or your caregivers believe would benefit your diabetes management, discuss this with your diabetes healthcare providers.

How many insulin pumps are available and how are they tested?

Today there are a handful or so of companies that manufacture insulin pumps around the globe. Prior to being made available for purchase, these insulin delivery devices are thoroughly tested by the manufacturer and reviewed by regulatory authorities, such as the Food and Drug Administration (FDA) in the U.S. Once a device is given the green light to be sold, it must be prescribed to the person with type 1 diabetes by their healthcare provider. Along with the prescription the healthcare provider gives specific instructions for how the insulin pump should be set up. Next the person with type 1 and their caregivers are taught by a healthcare provider, typically a Certified Diabetes Care and Education Specialist (CDCES), that is also a Certified Pump Trainer (CPT) for the insulin pump the user has chosen. Users of insulin pump therapy learn all the ins and outs of insulin pump therapy and the specifics about the particular pump they choose to use. In addition, manufacturers provide continuous 24/7 customer support to people who use their pump management system.

What are the 2 main types of insulin pumps?

The majority of insulin pumps available today are so-called tubed pumps.³ The tubing goes from the pump (the operating device that is worn on the body—e.g., the waist, in a woman’s bra, in a pouch around the waist, etc.) through a cannula (narrow, short tubing placed under the skin with a guide needle), placed anywhere insulin can be injected.

Figure 1. Tubed Insulin Pump

The other type of insulin pump is tubeless. In a tubeless system, a pod (that contains the insulin) is worn on a place on the body where insulin can be injected (such as the abdomen, back of arms, etc.) A very small amount of tubing connects from the pod through a thin plastic tube (a cannula) that is automatically inserted just under the skin (like insulin injections). The other piece of the tubeless system is the device from which the user directs the actions of the pod. A big benefit is that this piece, while it needs to stay near the user, does not need to be worn on the body.

Figure 2. Tubeless Insulin Pump System

The insulin pump user typically needs to change their pump tubing or pod site about every two or three days depending on several factors. Another benefit of a tubeless insulin pump management system is not having to deal with the inconveniences and challenges of the tubing becoming snagged or tangled (take for instance the simple and regular task of using the bathroom!).

Insulin pumps have been available for roughly four decades.^1,3 Through the years insulin pumps have gotten much smaller and easier to use. In addition, new features have been added to make insulin delivery easier and more convenient as well as features that can potentially reduce hypoglycemia (low glucose levels) and hyperglycemia (high glucose levels), such as the ability to consider insulin on board and to give more precise insulin doses. Over the last several years, as continuous glucose monitoring (CGM) has become more available, several insulin pumps can integrate and provide CGM data to the user and their healthcare provider for more precise and easier management.

Are there additional benefits of insulin pump therapy for a person with type 1 diabetes?

Yes, quite a few in fact! To name some:^2-4

Fewer calculations and less mental math to determine how much bolus insulin to take to cover food (meals, snacks) and to account for high or low glucose levels.

Greater personalization upon which to base optimal bolus doses. The individual insulin to carbohydrate ratio, insulin sensitivity factor, duration of insulin action, and more, are preset with a healthcare provider’s guidance. (These can be changed as needed.)

Fewer incidences of hypoglycemia (low blood glucose)^*

Set reminders and alerts to take your bolus insulin doses, check your glucose level, change your Pod, etc.

Access by the user and their healthcare providers to all of the insulin pump data. This can be as simple as knowing whether the user gave their meal time injection or accidently forgot it, along with the analysis of data by the user and with their healthcare provider to consider necessary changes to improve glucose management.

More accurate and smaller doses (if needed).

Fewer diabetes care supplies to carry because the user is, in essence, wearing their insulin (however, people always need to carry some backup supplies to be ready for emergency situations).

*Diabetes Spectrum 2019 Aug; 32(3): 194-204

Is insulin pump therapy right for me?

Choosing to start insulin pump therapy to manage type 1 diabetes for yourself or a loved one is a decision that you should make in concert with a diabetes healthcare provider. Insulin pump therapy may be a good option if you or a loved one:^2,3

need and want a less burdensome way to deliver insulin

have an unpredictable schedule day to day that results in varied insulin needs as well.
need very small amounts of basal insulin.
have higher and lower basal insulin needs during the 24 hours in a day.
travel across time zones or do shift work.
participate in athletics and/or intense yet irregular exercise.

want to give insulin discreetly

Is an insulin pump and the supplies typically a covered benefit by healthcare plans?

If you or your loved one have private health insurance, insulin pump therapy will typically be covered. Some people with other forms of state and federal government health coverage (Medicaid and Medicare) may cover insulin pump therapy. Interestingly the tubeless pump (Omnipod) may also be available through a pharmacy or Medicare Part D. The best way to learn about whether your health plan will cover the insulin pump you want, is to contact the insulin pump company. Their staff will help you determine your coverage.

Read real stories from people using insulin pump therapy to manage type 1 diabetes

Learn more by reading real life stories from people wearing pump therapy systems. Discover how insulin pump therapy is making a world of difference in their lives.

Resources
1: American Diabetes Association. 7. Diabetes technology: standards of medical care in diabetes - 2021. Diabetes Care.2021;43(suppl 1):S85-S99.
2: Walsh J, Roberts R. Pumping insulin, 5th ed.Torrey Pines Press. 2012.
3: Sikes KA, Weyman K. Diabetes and the use of insulin pumps. Endocrin Advisor. https://www.endocrinologyadvisor.com/home/decision-support-in-medicine/endocrinology-metabolism/diabetes-and-the-use-of-insulin-pumps/. Accessed March 3, 2021.
4: Scheiner G. Think like a pancreas. 3rd ed. Hachette Books. 2020.