A Standardized Glucose Data Display May Lead to Better Treatment
Managing diabetes has a lot to do with numbers, and analyzing them requires time and brainpower. Your doctor, nurse, and certified diabetes educator have to familiarize themselves with countless different glucose data reports—each multiple pages long—from various devices every day. “As a provider, I have to wrap my brain around how that particular device company shows the data,” says Davida Kruger, MSN, APN-BC, BC-ADM, a nurse practitioner at Henry Ford Health System in Detroit. And that takes precious time away from the patient.
But what if all device companies agreed to use the same glucose data report? That’s the idea behind what’s known as the ambulatory glucose profile (AGP).
The AGP is a one-page report of your glucose data, taken over two weeks and condensed into a single picture. “It helps you visualize how your blood sugars are doing … so you can take appropriate steps to try to get more time in your target range,” says Richard Bergenstal, MD, executive director of the International Diabetes Center in Minneapolis.
While the report is best used with a continuous glucose monitor (CGM)—you get up to 288 readings a day and 4,032 in two weeks—it works with finger-stick meters, too. It just won’t show as complete a picture, says Kruger. For instance, most people don’t check their blood glucose in the middle of the night, so no data would show up for that period of time.
Data readouts in a variety of report forms and on multiple pages force providers to take more time analyzing blood glucose data. The one-page AGP allows providers to instantly know what they’re looking at so they can spend more time reviewing data with you.
Many device companies already use or plan to incorporate the patented International Diabetes Center AGP into their displays. Others have chosen to create their own AGP-like reports, says George Grunberger, MD, FACP, FACE, chairman of the Grunberger Diabetes Institute in Bloomfield Hills, Michigan. That’s why the American Association of Clinical Endocrinologists published a consensus last year on minimal guidelines for what modified AGP displays should contain. The goal: moving closer to a standardized report.
The Big Picture
The official AGP report developed by the International Diabetes Center contains the following elements:
1. Glucose Exposure Your average blood glucose over 14 days, plus your estimated A1C
2. Glucose Ranges The percentage of your glucose data within, above, and below the target range
3. Glucose Variability The report shows two measures of how much the glucose readings varied from the average glucose over the two weeks. The two measures are called coefficient of variation (CV) and standard deviation (SD). In each case, a lower number is better.
4. Percentage of Time CGM Is Active This shows the amount of time (in a percentage) that your CGM was active and recording glucose data over the past 14 days. The higher the better, but if the number is 70 percent or higher, you and your health care team can feel comfortable that the AGP is a good reflection of your usual glucose profile.
5. AGP Display or Curve 14 days of glucose data condensed into a 24-hour picture. Pay particular attention to the gray shaded “target” area.
6. Orange Line This line represents your median glucose values, which means that half of your glucose readings are above the line, and half are below. Aim for a mostly flat orange line inside the target range.
7. Blue Shaded Area This area indicates where the middle half of your glucose levels lie. The more narrow the area, the less your blood glucose varies (or goes up and down).
8. Green Dotted Lines These are your outlier glucose values. Ten percent of your glucose values are above the top line, and 10 percent are below the bottom line. With fewer extreme readings, the green lines will be closer to the target range.
9. Daily Glucose Profile This panel shows each single day’s glucose pattern in a calendar format for all the days that are combined to give you the AGP display or curve.
The ambulatory glucose profile (AGP) is especially helpful in identifying glucose trends. Those include:
1. Spotting overnight lows. People often don’t feel the symptoms of hypoglycemia at night and end up sleeping right through it, says Richard Bergenstal, MD, executive director of the International Diabetes Center in Minneapolis. While meter users have to wake up and check blood glucose in order to collect overnight information, an AGP profile from a continuous glucose monitor (CGM) can illuminate overnight lows so your doctor can make treatment adjustments.
2. Making sense of finger sticks. You’re probably not going to learn much doing one finger stick at the same time of day every day, says George Grunberger, MD, FACP, FACE, chairman of the Grunberger Diabetes Institute in Bloomfield Hills, Michigan. For those not on insulin (people on insulin are advised to check more frequently), consider doing two finger sticks daily at different times of the day for a few weeks. You can use the resulting AGP graphics to glean useful information about when you may be high or low.