Technology and Diabetes: How insulin gets in the body

Did you know that insulin was discovered in 1921?! Yes - insulin has been celebrating its 100 years since discovery the entire year of 2021. Prior to the discovery of insulin, individuals diagnosed with diabetes had to be on extremely restrictive diets to try to aid in blood sugar control and life expectancy past 10 years after diagnosis at that time was upsettingly low. 

However, this all changed with the discovery of insulin. In fact, Drs. Banting and McLeod won the Nobel Prize for this life-changing discovery! 

The insulin used at that time was derived from cows and over the years that followed, further advances led to the introduction of human insulin and later synthetic insulin into the market. 

Not only has the technology of the type of insulins available changed over the decades since the discovery of insulin, but the mechanism or modality by which insulin can get into a person’s body has evolved over the years as well. 

Here is a review of methods by which someone who needs insulin therapy can get insulin into their body. 

Vial and Syringe

Syringes used to be glass! AND it was the same syringe used for multiple injections, so after each use, the individual had to boil this glass syringe in order to sterilize it between injections. You can imagine the nuisance this was! 

Nowadays, we have plastic syringes for single use, which means that a new syringe is used with each injection. The syringes are placed into an insulin vial and the appropriate dose of insulin is drawn up into the syringe for injection. 

Some people today still prefer to use a vial and draw up their insulin via a syringe for injection - and that is A-OK!

Insulin Pens 

Insulin pens differ from syringes because within each pen is a fixed amount of insulin. Depending on the type of insulin, the total units of insulin in each pen varies, but as an example, many insulin pens store 300 units of insulin. 

At the end of the pen is a dial and the person dials the dose they need prior injecting the insulin just under their skin. Once all the insulin in the pen has been used up, the pen is thrown away and the person reaches for a new one. While each pen can be used multiple times, a new needle is placed on the end prior to injection (for infection prevention and pain reduction purposes!). 

Smart Pens

These are newer evolutions of the insulin pen described above. Here, this pen is bluetooth enabled and communicates with an app on a smart phone. It lets a person know when an injection was given (provides a timestamp for the injection - especially useful for people who can’t remember if they actually gave themselves an injection or not; yes, it happens!), what the dosage was, and can even estimate much of a previous insulin dose is likely still circulating in the body. How cool!

Only rapid acting insulin (the insulin used for meals) is used in smart pens and the pen does not get thrown away when the insulin is used up. Instead, the person swaps out cartridges within the pen.

Insulin Pumps

These are little machines that are either clipped to clothing or worn on the skin. They continuously infuse insulin just under the skin and the person wearing the pump can adjust the amount of insulin they are programmed to get, depending on food intake or exercise. 

Insulin pumps are not the same thing as a pancreas. The person using this technology needs to program the settings and let the pump know when they are going to eat and calculate how many carbohydrates they are eating in a meal and what the blood sugar is at the time of the meal. The pump then does a calculation and makes a recommendation for the insulin dose needed for the meal. 

Upkeep is not trivial - there are cartridges of insulin within each pump and the person needs to make sure there is always enough insulin in this cartridge. Also, it is important that the infusion site, the part of the skin where insulin is infused, gets switched frequently to avoid the build-up of scar tissue around the infusion site. Buildup of scar tissue reduces how much insulin actually gets delivered.

So while pumps are great for the person who is ready for the task - it’s important that an individual understands that it requires a good amount of work!

Wearable insulin delivery

These types of patches were developed to make insulin delivery easier and differ from insulin pumps as follows:

• They are disposable and changed out either every day or every 3 days, depending on what patch you are wearing.

• By pressing a button, a fixed amount of insulin gets dispensed just under the skin. If each button press is 2 units, then clicking the button 3 times gives 6 units of insulin.

• They also have the benefit of being more discrete and clicking the button can be a discrete move as well. Insulin pumps usually can be seen and can therefore draw attention, which some people don’t like.

Inhaled insulin

Yep - people can inhale insulin!

When insulin is inhaled, it enters the bloodstream quicker than when it is injected, even more quickly than ultra-rapid acting insulin. Not only is it quicker in when it starts to have an effect, but it quickly leaves the system as well. 

This speed of action is attractive to people who are frustrated with the rapid-acting injection insulins still not being rapid enough.

As an added bonus for some, it does not involve needles.

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Since the discovery of insulin, there have been so many advances in how insulin can get into a person’s body. It is important that medical professionals and patients with diabetes know what the insulin delivery options are when trying to customize a diabetes treatment plan. With the knowledge of the strengths and weaknesses of each option, a person can try out the insulin delivery options to best find the one that reduces the burden of insulin delivery and helps keep blood sugar levels at target.