Originally published March 13, 2018.

For the first time in a decade, people with diabetes in the U.S. who are not using an insulin pump can get a stand-alone continuous glucose monitor (CGM) from Medtronic Diabetes.

The company announced March 12, 2018 that it had received FDA approval four days earlier for its Guardian Connect system, after regulators spent two years (!) reviewing this smartphone-compatible medical device that’s been on the market overseas since 2016.

In a nutshell, the new Guardian Connect marks Medtronic’s return to the stand-alone CGM market, a shift from its aggressive marketing in recent years pushing customers to purchase an insulin pump-CGM combo system.

While it uses the same Guardian 3 sensor approved for use with the Minimed 670G hybrid closed loop system, this new stand-alone CGM has a different transmitter with built-in Bluetooth Low Energy (aka Bluetooth 4.0). That allows the transmitter to share data directly with a smartphone, notably bypassing the need for a separate dedicated receiver device.

This is a first for the FDA and is probably the reason it took two years of consideration before approval. As the first so-called “smart CGM” that needs a smartphone and mobile app to function, this could re-shape the conversation on insurance and Medicare coverage for diabetes tech tools, as it makes the smartphone a necessity, rather than an optional extra.

We’ve got a rundown below on the product specs for this new Guardian Connect CGM, which is now available to purchase as of June 13, 2018.

The Hardware

The last stand-alone CGM that MedT offered was the Guardian Real-Time system in 2007, and about six years ago they also launched the mySentry display monitor with limited-range data sharing capabilities. Since then, the company’s been leading people toward combo systems, leaving any adults on injection therapy with no option to purchase just the CGM (and the past three combo systems not being approved for young kids). Also in 2015, the company launch its Minimed Connect display platform that brought some data-sharing capabilities to its 530G system, but again that was based on a combo system with their insulin pump.

Here’s a rundown of the new stand-alone system, which has been years in the making since we first covered it in 2014. It started shipping mid-year 2018.

No Dedicated Receiver: This is new for the CGM market. Unlike the two competing devices from Dexcom and Abbott, this one from MedT does not require a separate receiver device be sold as part of the package. Rather, it talks directly to a smartphone (the way it should be!), so clearly you need a smartphone to use it.

Same Sensor: Yes, it does use the same Guardian 3 sensor that goes with the Minimed 670G here in the USA (as the stand-alone CGM globally uses an older-generation of MedT sensor). The Guardan 3 sensor has accuracy in the 9-11% range (not too different from Dexcom and the Libre, overall) and it’s approved for seven-days of wear and in February 2018, this sensor was FDA-cleared for wear on the upper arm along with the abdomen.

Different Transmitter: The meat of this Guardian Connect stand-alone CGM system is a new transmitter, one that has the same seashell-shape design but has Bluetooth Low Energy built in. That allows it to beam glucose data directly to the smartphone every five minutes. The transmitter has a 12-month warranty and is rechargeable, and there’s no other size or adhesive change with this transmitter.

Not Pump-Connected: As a result of the above change in the transmitter, this system will not connect with the Minimed insulin pumps. Medtronic is also working to develop next-generation versions of devices that will have BLE and allow for direct data-sharing. Getting this Guardian Connect transmitter with BLE was the first step, and they’ll now pursue bringing this connectivity to its next-gen devices.

No Dosing Decisions: Of the three CGM devices on the market, Medtronic remains the only one that isn’t designated as a “therapeutic CGM” and therefore isn’t FDA-cleared for users to make insulin dosing or treatment decisions from the data. Both the Dexcom CGM (G5 and G6 models) and Abbott Libre Flash products are approved for that use (if one’s comfortable with that), and therefore they don’t require fingerstick calibrations. Medtronic has not been designated by the FDA to be accurate enough for dosing decisions, so at least two daily fingerstick calibrations are required and recommended.

Not for Kids: Medtronic says the new stand-alone is FDA-approved for those aged 14 to 75 years. We asked about the company’s plans for pediatric clinical studies to seek regulatory approval, but MedT said it was not able to share any timeline for that.

Water-Friendly: The Guardian Connect transmitter/sensor can be used when showering or swimming, safe for submersion up to 7.5 feet for 10-minute periods.

The Mobile App(s)

CGM App: The Guardian Connect mobile app is free. At the time of launch, it was only be for iOS users and an Android version of the mobile app was in development. UPDATE: Medtronic Diabetes announced in May 2020 that the FDA had approved its Android app for the Guardian CGM. It will be available starting in Summer 2020.

Sugar.IQ: This is a separate mobile app that Guardian Connect CGM’ers will have “exclusive access” to. It’s the IBM Watson app that Medtronic’s been talking about for a few years now, but remains unavailable for most PWDs. They launched it to a small beta-testing group in Fall 2017 and we’re told that what they learned from initial users will help inform the commercial launch and further app development. The app uses IBM Watson analytics to find patterns in diabetes data and offers real-time, actionable and personalized insights, which includes a circular graph reflecting time-in-range data and a Glycemic Assistant for food info. Medtronic has presented scientific sdata that people using the Guardian Connect system with the Sugar.IQ app experienced 4.1% more Time in Range (63.4%) compared to Guardian Connect alone (59.3%) which represents about one extra hour per day. Additionally, those who also used the optional Glycemic Assist feature to review their response to specific foods increased Time in Range by an additional 4% compared to those not using that feature.

Touchscreen: In true smartphone form, you can use your finger to trace CGM data lines, expand or contract the view for whatever the glucose period of time you’re looking at.

Customizable Alerts: The user can set the predictive alert for any timeframe they wish, from 10 minutes to 60 minutes in advance of a predicted low or high blood sugar. You can also program different glucose thresholds and alerts for different times of day (i.e. Day vs. Night, or any other two periods of the user’s choosing).

Snooze Feature: Alerts can be “snoozed” for 10 to 60 minutes so the same alert won’t be repeated during that snooze period; but at the end of the snooze period it will repeat if the user is still high or low. You can also apply the phone’s Audio Override feature to predictive alerts so you don’t miss important notifications even when the phone is on silent or in Do Not Disturb mode (commonly used at night or during work meetings, etc). In an updated version expected in summer 2020, the app will have new personalized volume adjustments, including the ability to mute alerts when individuals do not want to be disturbed for a period of time.

Data-sharing: Like everything with MedT, this new system communicates with their CareLink software platform. The transmitter talks to the smartphone, which shares data to the Guardian Connect app and then to CareLink via the Internet. From there, you can connect with the Sugar.IQ app for more detailed feedback and insights. You’re also able to send free text message notifications for high and low glucose alerts to caregivers on their phones, as well as other Guardian Connect notifications. As many as five people can have direct data-sharing access, and you can also view CGM data online through the CareLink Connect portal.

Smartwatches: You can get alerts and status notifications on the Apple Watch, as well as other iOS app notifications. Additional Apple Watch features, such as viewing current sensor glucose level, are planned for future versions of the Guardian Connect app. Clearly, as the Android platform work moves forward, it’s likely Medtronic will finally be able to tap into Samsung wearables as predicted in big news a few years ago but hasn’t materialized yet.

Interoperability: Medtronic tells us it will only allow data-sharing directly to CareLink and subsequent apps, and their system will not be opened up to connect with other data platforms. However, remember that Medtronic previously reached an agreement allowing Glooko to access CareLink data, so we’ll see what materializes on that (and always remember to read the fine-print of any data-sharing platform on who owns your data).

For more info, here is Medtronic’s Guardian Connect product page.

Availability and Cost

Medtronic will be doing a limited, incremental launch between July and August 2018, with more broad availability coming afterward. This is similar to their rollout of their Minimed 670G hybrid closed loop system — which was approved in Sept. 2016, had limited shipments in Spring 2017 and more broad access in summer and beyond (though manufacturing delays complicated that launch).

Medtronic’s marketing folk say this Guardian Connect starts at only $50 a month, which is the “lowest cost of any personal CGM system.” This calculation is based off typical patient responsibility for 20% co-insurance, and average Medtronic sensor order rates, we’re told. Remember, this doesn’t include a separate receiver device like other CGMs so you’re only paying for the transmitter and Guardian 3 sensor.

  • The mobile apps – Guardian Connect and the Sugar.IQ apps: both free
  • Transmitter (has a 12-month warranty): $775
  • Guardian 3 sensors (five-pack, each approved for seven days): $553
  • Insurance: Your Coverage May Vary, of course (MedT notes it has coverage with 600+ plans nationwide)

“At launch, the Guardian Connect system is expected to be reimbursed by commercial payers for most people with type 1 diabetes,” Medtronic’s Pamela Reese said. “Some type 2 diabetes patients on MDI will also have insurance coverage for standalone CGM. Coverage and pre-approval requirements are similar to those for patients using CGM with an insulin pump. We will continue to add payers as available and we will pursue coverage for other patient populations over time.”

Medicare coverage is a work in progress. As noted, the fact that Guardian Connect is the first system requiring a smartphone and mobile app for core functionality could certainly change how the Centers for Medicare and Medicaid Services (CMS) view CGM and medical device coverage decisions — which typically impacts how commercial insurers move forward.

We’re glad to see Medtronic finally offering PWDs the option to use the CGM alone if they don’t want an insulin pump. This has been a long time coming, and in these days where everyone’s talking about the future of CGM tech, it’s great to see options expand alongside Dexcom and Abbott in the CGM market.