Why the Medtronic 530G is NOT an Artificial Pancreas

by Leighann on October 4, 2013

I always say that every pump has its positives and negatives. You have to sit down and make a list of pros and cons about all of the pumps on the market. You need to decide which features are important to you and your child. What is right for one family isn’t necessarily the best choice for someone else. There is no right or wrong answer.

When we began researching pumps, we made the best decision for our family. It was the right decision. Is the pump 100% awesome 100% of the time? No. It’s not. But for us, it’s certainly better than the alternatives.

I just want to be up front that I am not a spokesperson for any insulin pump or continuous glucose monitor manufacturer. In the past year, I did write for Insulet’s Suite D blog and plan to continue writing for them. And I have been to Medtronic headquarters a couple of times. I am not paid to write about these products on this website. And I’m so honest sometimes (like my face to face conversation with the higher ups at Medtronic) that sometimes I’m surprised that they still talk to me. But hey, I give them honest feedback.

So I have some opinions about Medtronic’s new pump/CGM. But my opinions aren’t about whether or not it’s a good pump or a good choice for you or your child. I have a few things to say about the FDA and why we should be asking for more.

Artifical Pancreas Device System

(Image source: FDA website)

Artificial Pancreas Threshold Suspend Terminology

So, here’s where I’m going to insert some opinions. I have to say I was really irritated when I started seeing posts early in the morning about the approval of this “artificial pancreas.” (I may also refer to it as the AP or bionic pancreas.)

This is NOT an artificial pancreas.

But lots of parents on Facebook were either confused or were jumping for joy because they didn’t know the AP was going to get approval so quickly.

This might be the first step to the artificial pancreas, but it is not the full artificial pancreas!

There are currently many clinical trials underway in adults and children working toward the development and approval of a fully functioning artificial, or bionic, pancreas. This is a “closed loop” system meaning that, in simple terms, the insulin pump and continuous glucose monitor talk to each other and make decisions based on complex algorithms. The system will be made up of an insulin pump, a CGM, and a way to give glucagon. One of the issues is creating a stable form on glucagon that doesn’t have to be replaced every 24 hours.

In the full bionic pancreas insulin will be given when blood sugars begin to rise and glucagon will be given when blood sugars drop and/or basal insulin will be reduced/suspended. You (or your child) will not have to count carbs or enter in blood sugars for boluses.

(Also, this video about “inhaled insulin” to supplement the AP is interesting.)

So if the Medtronic 530G isn’t a full artificial pancreas device system why is Medtronic calling it an artificial pancreas?

Because they can.

As part of the approval process, the FDA created the artificial pancreas device system (APDS) category:

“The FDA is helping advance the development of an artificial pancreas device system (APDS)—an innovative device that automatically monitors blood glucose and provides appropriate insulin doses in people with diabetes who use insulin.

FDA’s efforts include prioritizing the review of research protocol studies, providing clear guidelines to industry, setting performance and safety standards, fostering discussions between government and private researchers, sponsoring public forums, and finding ways to shorten study and review time.

FDA’s release of Final Guidance for Industry and the Food and Drug Administration Staff: The Content of Investigational Device Exemption (IDE) and Premarket Approval (PMA) Applications for Artificial Pancreas Device Systems will help provide clarity for manufacturers, investigators and reviewers in the development of this important technology. It allows manufacturers and researchers to be innovative and flexible in how they develop studies. It also promotes greater communication between the FDA and manufacturers and researchers, which will support the rapid, safe and effective development of an APDS.”

Here are the types of APDS’s (from the FDA’s website):

Threshold Suspend Device System

The goal of a threshold suspend device system is to help reduce the severity or reverse a dangerous drop in blood glucose level (hypoglycemia) by temporarily suspending insulin delivery when the glucose level falls to or approaches a low glucose threshold. These are sometimes referred to as “low glucose suspend systems.”

This kind of system serves as a potential back-up when a patient is unable to respond to a hypoglycemic event. Patients using this system will still need to be active partners in managing their blood glucose levels by periodically checking their blood glucose levels and by giving themselves insulin or eating.

Control-to-Range (CTR) System

A CTR system reduces the likelihood of a hypoglycemic event or a hyperglycemic event (when blood glucose is dangerously high) by adjusting insulin dosing only if a person’s glucose level approaches the low or high glucose thresholds. Patients using this system will still need to check blood glucose levels and give themselves insulin to maintain control of glucose levels.

Control-to-Target (CTT) System

A CTT system sets target glucose levels and tries to achieve these levels at all times. This system is fully automated and requires no interaction from the user (except for calibration of the continuous glucose monitoring system).

CTR and CTT System Subtypes are dependent upon the drug or drugs being delivered and how each drug affects glucose levels. Three subtypes are being investigated: insulin-only, bi-hormonal and hybrid:

An insulin-only system achieves a target glucose level by increasing or decreasing the amount of insulin infused.

A bi-hormonal control system achieves a target glucose level by using two algorithms to instruct an infusion pump to deliver two different hormones – one hormone (insulin) to lower glucose levels and another (such as glucagon) to increase blood glucose levels. The bi-hormonal system mimics the glucose-regulating function of a healthy pancreas more closely than an insulin-only system.

A hybrid system allows the patient to supplement insulin automatically prior to a meal. This pre-meal supplement decreases the risk of hyperglycemia after eating.

Yes, technically the Medtronic 530G is considered an artificial pancreas because it is approved for use by the FDA under this category, but it is only the very first step. The “closed loop” is the final product.

The Medtronic 530G does one thing now that other existing products on the market do not do: it shuts off basal insulin delivery if the low threshold has been reached and the alarm is not responded to. Nothing more.

Your child still has to check blood sugars throughout the day.

Your child still has to count carbs.

Your child still has to treat lows.

Your child still has to treat highs.

Your child still has to compensate for activity.

Your child still needs constant care.

It’s not a game changer.

I know you now think I’m a Negative Nelly. Of course it’s great that the first milestone on the way to an FDA-approved artificial pancreas has been reached. But, like I’ve said, it’s a first step. There’s no reason to throw a party. And there’s certainly no reason to stop funding research!

Here’s what I will say: Kudos to Medtronic for finally getting this technology approved in the US. (It’s been available overseas for some time.) If I had a child who was already using the Medtronic insulin pump and CGM, of course I would consider upgrading to this new device.

As I understand it, the CGM is still going to alarm and you are still going to have to react to it. The low threshold suspend only kicks in if you don’t respond. Parents are still going to be getting up in the night to give juice boxes to treat lows. Turning off basal doesn’t instantly bring up blood sugars.

Yes, it is a safety feature that will hopefully make some parents sleep easier.

But I demand more.

What do we want?!

A fully functioning closed loop artificial pancreas device system!

When do we want it?!

Before our kids go to college!

So here’s my issue, what if the general public, those who contribute to the JDRF and other groups funding AP research and trials, stop giving because the “artificial pancreas” is already on the market.

There are already news stories about this revolutionary new device with headlines that make you think that the full artificial pancreas is available and will be in the hands of people with diabetes soon.

Like this one: Petersburg woman first in Indiana to get artificial pancreas

(E-mail and feed subscribers click over for embedded video.)

As if there aren’t already enough misconceptions out there about diabetes. When people read headlines and hear stories like this one, they will assume that managing diabetes just got a whole lot easier. It hasn’t.

What do you think? (About any of this: calling this an artificial pancreas, the new pump or sensors, etc.)

And Another Thing…

More posts about insulin pumps

More posts about low glucose suspend

More posts about the artificial (or bionic) pancreas

More posts about the Food and Drug Administration (FDA)

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