Imagine for a moment that you are an ER doctor. Your patient is a 57-year-old white male with type 2 diabetes complaining of chest pain. You immediately order an EKG to see what’s happening with his heart. Within minutes, the tech brings you a report.
But last week the hospital bought a new EKG machine and you find its report baffling. You are familiar with a couple of different models, but this new one isn't like anything you’ve ever seen before and you can't make any sense of it. You can’t even figure out if your patient’s heart is beating normally or irregularly...
Luckily, this never happens in the real world. All EKGs, regardless of manufacturer, use a standardized report format.
The same cannot be said for glucose meters and CGMs (continuous glucose monitors), however, that patients and doctors use to track blood sugar levels of people with diabetes. With these devices, reports depicting blood glucose values have historically been proprietary, and vary hugely between manufacturers.
Why isn’t there a standardized report for blood sugar data, as there is for EKGs?
Actually, there is one. It’s been slow in coming, but is now gaining traction. You might even have seen one and not realized it. It’s called the Ambulatory Glucose Profile, or AGP.
Its origins date back to the late 1980s. It was developed by a team at the Albert Einstein College of Medicine headed by Dr. Roger S. Mazze. In its original incarnation, the AGP served as a way of graphically presenting multiple days of data from fingerstick meters -- a huge improvement over traditional patient-kept checkbook-style paper logbooks.
Dr. Mazze later moved to the International Diabetes Center (IDC) headquartered in Minneapolis, where work on the AGP continued under the leadership of Dr. Richard M. Bergenstal after Mazze’s retirement. By 2008, the IDC team realized that, as with EKGs, diabetes treatment professionals would benefit from a standardized glucose report, and began advocating for their AGP to take on that role. For that reason, Dr. Bergenstal is viewed as the "father of AGP" by many in the diabetes field.
Along with establishing a licensing agreement with Abbott Diabetes Care as the first to adopt the AGP use, the IDC later got a grant from the Helmsley Charitable Trust in 2012, and assembled an expert panel to help shape the AGP report’s key elements. By 2017, the American Association of Clinical Endocrinologists endorsed the AGP.
So, what does this universal report look like?
What is the Ambulatory Glucose Profile (AGP) for Diabetes?
First and foremost, despite the reams of data used to create it, the AGP is a one-page report. The center of the page is dominated by a large graph that’s been the heart of the report since the beginning: Multiple days of glucose data are overlaid upon each other to make the spotting of trends easy and intuitive.
Across the bottom of the report pages is an EKG-like strip graph showing daily data. Across the top are metrics such as average glucose, measures of variability, Time-in-Range, and predicted A1C based on the aggregate data. It also shows the percentage of time a PWD (person with diabetes) spends in either hypoglycemic or hyperglycemic states.
How is CGM Data Translated into an AGP?
In its earliest form, the AGP report was an Excel-based tool, but has since been developed into a robust embeddable code by Sursumcorda and Thoughtworks. The code captures the flood of raw data from blood glucose measuring devices and presents it in the one-page universal format.
IDC licenses the code and the process to device companies and data aggregators, Bergenstal says, explaining that the IDC chose to go this route as it didn’t want to become a data clearing house.
Diabetes Devices Using AGP
The first AGP-enabled device with built-in AGP reporting was Abbott’s European FreeStyle Libre Flash CGM in 2014. The next year, Diasend became the first diabetes data aggregator to license the AGP. Now the list of diabetes companies using AGP reads like a veritable Who’s Who of the diabetes tech ecosystem: Bigfoot Biomedical, Dexcom, Glooko, Medtronic, and Roche, to name a few.
No. But not because they don’t like it. It's more a matter of time and resources. Tidepool Founder and CEO Howard Look (a D-Dad himself) tells DiabetesMine, “We love AGP and it’s definitely something we’d like to add to Tidepool. We’ve applied for funding grants to get AGP done, but haven’t received any yet.” He says they remain optimistic that they’ll be able to incorporate it in the future.
How much does it cost to license AGP? Bergenstal says the licensing fee varies with the amount of support the client needs, but ranges between $10,000 and $50,000. He notes that the AGP is not a profit center for the IDC, but the money is used to cover staff time needed to transfer the code and get it up and running.
Bergenstal says they don't see the cost as a potential barrier to universal adoption. “We don’t think the fee has been a barrier to anyone,” says Bergenstal, who describes it as a “small fee.”
Widespread Adoption of the AGP?
We asked Dr. Roy Beck, the Time-in-Range guru, what sort of awareness there is in the medical trenches about AGP. He told us, “I think AGP is still in its infancy towards wide adoption, but I have been extremely impressed with how quickly use has expanded in the last year—due to greater use of CGM and to the CGM companies such as Dexcom incorporating the AGP report.”
He also says that specialist docs, like endos, have a higher awareness of AGP, while primary care physicians (PCPs) have “very little at present.” He adds that primary care doctors, ironically, are likely to learn about the AGP report from their patients. “I think PCPs will learn about AGP from patients who get started on CGM and have AGP printouts to review with them.”
Bergenstal agrees that the adoption has been “a little slow” in coming, but says that once a few companies were onboard, “it just took off.” He also says it makes him smile when he hears CGM and AGP being used synonymously in conversations he has with other medical professionals.
But the AGP isn’t just for doctors! We PWDs can learn a lot about our diabetes—and take actionable steps to improve our diabetes control—by understanding how to read the one-page AGP report ourselves.
How Patients Can Use the AGP Report
AGP isn’t like an open source app that you can download and works for any device. It’s licensed by the IDC through its industry partners, but it’s increasing being found in a wide variety of reports that PWDs can download from their various devices. Dexcom Clarity, for instance, has an AGP tab in its reports window.
The IDC’s Education Resources department recommends—after being sure the report reflects at least 10 days of data—that patients look first at their Time-in-Range. This is often shown as a color-coded bar graph on the upper right side of the AGP report (there are some variations from device to device in the finer details of the report). The current goal is to be in target range 70% of the time, with less than 3% of the time below 70 mg/dL.
Says Beck: “Time-in-Range is a more actionable metric for patients using CGM than A1C. Patients can see an impact of changes in diabetes management within a week on TIR, whereas the changes take many weeks to be reflected in A1C. It also is more intuitive to think about improving your TIR by 30 or 60 minutes per day as opposed to trying to improve your A1C by one half of one percent.”
Next, a large glucose profile graphic dominates the report—most often representing CGM data, where AGP is gaining the most traction. Rather than creating a spaghetti graph of individual glucose traces from each day overlaid, the AGP blends the glucose readings into a one smooth multi-shaded graph. At a glance it looks like an aerial view of a river canyon on a topographical map. A dark line down the center, the river, shows the median of all the readings. A darker band on either side of the river marks 75% of the readings. Finally, a lighter band outside of that shows the extremes of both the highs and the lows.
The IDC recommends that patients write the times of their meals, meds, and activity right on a prinout of the graph to help them spot trends. They advocate paying special attention to times of day when the sugar is lowest and highest, as well as when the readings are most and least consistent. Areas where the “canyon” is narrow shows the times of day when there’s not much variability in the glucose readings. Times of day with a wide canyon show larger variability. The experts also advise PWDs to compare current reports to past ones to see if changes are having positive or negative impacts. And of course, the IDC urges all changes to be made in coordination with your medical team.
Hopefully someday soon, we—like EKGs—will all be on the same page. The single page of the AGP report, that is.