Blood Sugar Monitors That Communicate With Insulin Pumps

If you have recently been diagnosed with diabetes, you may be learning about continuous glucose monitors (CGMs) and insulin pumps for monitoring and managing your blood sugar.

You may also have heard about CGM and insulin pumps that pair together. This system allows your insulin pump to adjust its insulin delivery in real time according to readings from your CGM. This is known as sensor-augmented pump (SAP) therapy.

This article discusses the benefits of insulin pumps that pair with CGMs. It also includes a comparison chart with the different devices available, along with troubleshooting tips you might need when pairing them.

Managing Your Blood Sugar

Managing your type 1 or type 2 diabetes starts with monitoring your blood sugar. Two types of devices are used to monitor blood sugar:

• A glucometer, which uses a finger prick sample of your blood to measure your blood sugar
• A continuous glucose monitor, which automatically tests your interstitial glucose level—the glucose in the fluid between your cells—every few minutes

All people with type 1 diabetes and some people with type 2 diabetes also need to take insulin to manage their blood sugar levels. Insulin may be administered in two ways:

• One or more insulin injections given daily using a needle or pen
• An insulin pump that delivers insulin through a thin tube under your skin and into your bloodstream
  

CGMs have become more common among people who take insulin therapy. CGMs keep a close tab on your blood sugar for you, and they will alert you with an alarm or smartphone app when your blood sugar is increasing, decreasing, or stable.

Using Sensor Augmented Pump Therapy

Sensor augmented pump therapy offers another level of convenience that can further streamline your diabetes care strategy and give you more control over your blood sugar.

Here's how SAP works:

1. To get started, you and your doctor will work together to program your SAP with preset values that tell your insulin pump when to slow or resume insulin delivery.
2. Next, you will attach a glucose sensor to your skin. Its needle goes under your skin and is then removed so that just the sensor remains.
3. The sensor will continuously monitor your interstitial glucose levels and send readings about your blood sugar to your smartphone app.
4. When your glucose sensor detects that your blood sugar is approaching one of your preset values, the insulin pump will suggest a change in your insulin dose or automatically adjust your insulin accordingly.

The constant communication between your CGM and insulin pump can help protect you against sudden spikes in your blood sugar. SAP isn't 100% autonomous, though; you will still need to manually control insulin delivery at mealtime.

Benefits of Communication

SAP therapy drastically reduces the risks of hyperglycemia and hypoglycemia, because it enables your CGM to automatically alert your insulin pump when it should reduce or resume insulin delivery.

The practical and medical benefits of SAP therapy are well documented. Numerous studies have shown that SAP is effective at keeping blood sugar low while also reducing the risk of hypoglycemia.

Furthermore, SAP therapy has shown itself to improve long-term health outcomes. For example, in one study, people who took SAP therapy lived an average of nearly four years longer than people who only took daily insulin injections.

The study also showed that, although SAP therapy costs more than multiple daily insulin injections, people who used an SAP were less likely to have diabetes-related complications like heart or kidney disease. As a result, the overall financial burden of their medical care was lower than those who didn't use an SAP.

SAP has psychological and social benefits for many users too. This was demonstrated in a 2013 study of 334 adults and 147 children with diabetes, some of whom used SAP while others continued their daily insulin injections.

While the children in this study mostly benefited from the convenience of SAP therapy, the adults reported that SAP had a positive impact on their social lives and gave them more freedom in their day-to-day activities.

CGM-Compatible Pumps

SAP therapy with CGM-compatible insulin pumps offers several advantages, including:

• With SAP, you get real-time data about your glucose levels, often via a discreet smartphone app.
• Some insulin pump and CGM pairs can predict when your glucose will rise or fall and adjust insulin delivery in advance.
• Pairing is effective at preventing hypoglycemia, especially at times when you are asleep or unable to check your blood sugar.
• CGMs eliminate the need for finger pricking, making them a great option for children.
• CGMs allow parents and caregivers to monitor their child's blood sugar remotely while the child is away at school, camp, or a friend's house.

As of mid-2021, there are four CGM compatible insulin pumps available on the market:

Of the four CGM-paired insulin pumps available, there are two automated insulin delivery (AID) systems: Tandem's t:slim X2 insulin pump with Control-IQ technology, and Medtronic's MiniMed 770G.

AID systems are also known as hybrid closed loop systems because they function somewhat like an artificial pancreas. Each AID system consists of a CGM that predicts when glucose levels could drop and an insulin pump that automatically adjusts to keep glucose stable.

The FDA is expected to approve a third AID system by Insulet—known as the Omnipod 5—by the end of 2021. Unlike the t:slim X2 and the MiniMed 770G, the Omnipod 5 will be the first tubeless AID, combining the Omnipod patch pump with the Dexcom G6 CGM.

Troubleshooting Problems

Switching from a glucometer to a CGM can take some getting used to. Even if you have experience with a CGM already, you still might have to do some troubleshooting when it comes to pairing.

If your pump won’t stay connected to your transmitter, there are a couple of things you can try before giving the product's manufacturer a call:

• You might be too far from your phone: If you’re using a smartphone app that communicates with your transmitter, you’ll need to keep your phone close—otherwise, your insulin pump could disconnect.
• Your pump and transmitter might not “see” each other: Your transmitter needs to be located on the same side of your body within view of each other for them to connect. Make sure there are no body parts or clothing items blocking them from communicating.
• It might be time for a new transmitter: For example, Dexcom transmitters are only in warranty for 90 days and will stop working after 112 days. Keep track of expiration dates and order replacements well before they expire.
• Your transmitter may not be placed properly: Check to see that your transmitter is snapped securely into your sensor pod. You may have to wiggle it around some before it clicks into place.
• You may have more than one transmitter connected: Only one transmitter can connect to your insulin pump at a time. Go through your settings and double-check that you haven’t connected any other transmitters.
• You might have pressed airplane mode: Find airplane mode and make sure that it’s turned off. This can easily happen with insulin pumps that have particularly sensitive touch screens.
• Your pump may need new batteries: Keep at least one extra set of batteries in your purse, kit, car, and home in case you need to change them.

After trying any of these tips, give your devices some time to reconfigure and find each other. You may need to wait up to 15 minutes between each attempt to see if they reconnect.

Summary

SAP therapy offers many medical and practical benefits for adults and children alike. Having your insulin pump paired to your CGM makes tracking your blood sugar in real time more convenient and can help you sleep better at night.

CGM-compatible insulin pumps and hybrid closed-loop systems aren’t completely autonomous. They still require you to manually control insulin delivery at mealtime. And while you won’t have to use finger sticks as much, you may still want or need them to calibrate your devices and verify your glucose readings.

A Word From Verywell

Diabetes care technology is constantly evolving and creating more opportunities for you to find the perfect system for your needs. Unfortunately, many insurance providers aren't progressing quite as fast.

In terms of CGMs and paired insulin pumps, your insurance provider may not foot the bill if you are already managing your diabetes well with a glucometer and insulin injections. Before you make any purchases, make sure you clear it with your doctor and insurance provider.