Continuous glucose monitors (CGM) have become an essential component of diabetes management. CGM use has increased significantly over the past 5 years, especially among very young and school aged children. We know that people who use a CGM have better diabetes outcomes as measured by HbA1c, and CGM alerts can also help reduce and prevent hypoglycemia. Finally, CGM data can be shared with family members and caregivers to improve communication and reduce stress.
- Know where you are. When you want to know your blood glucose number, simply look at your receiver or connected smartphone. You don’t have to take out a meter and do a fingerstick.
- Know where you are going. CGM have trend arrows, so you can see if your glucose is rising or falling. This will help you make a more informed decision. For example, before exercise, your glucose is 150 mg/dL. If you also see trend arrows on the CGM indicating your glucose is rising rapidly, you may decide to go ahead with your workout. However, if you see trend arrows on the CGM indicating your glucose dropping rapidly, you might consider having a snack or suspending insulin delivery on your insulin pump.
- Understand cause and effect. CGM help you understand the effect that certain foods, activities, and behaviors have on your glucose numbers. Are you going low after exercising? Are your numbers spiking over 200 mg/dL every time you treat a low? What happens when you give insulin fifteen minutes before eating instead of waiting until after the meal? Knowledge is power, and the trend line on your phone or receiver holds a world of insights.
- Review your data for trends. CGM data should be reviewed every 1-2 weeks to identify trends. These data can help you work with your diabetes care team to make adjustments to your insulin regimen and diabetes care plan.
- CGMs can send alerts. Aside from the constant stream of data, most CGMs can send alerts telling you when your blood glucose levels are rising too high or dropping too low.
Time in Range
“Time in range” is a relatively new term that describes the amount of time your glucose is between 70-180 mg/dL. When you are below 70 mg/dL, your brain does not have enough glucose to function well, and you may feel the effects of hypoglycemia. When you are above 180 mg/dL, the kidneys filter glucose out of your blood, causing them to work over time. Keeping glucose levels between 70-180 mg/dL reduces your risk for short and long term diabetes complications.
To get started, review your time in range for the past 14 days to get a baseline. The ultimate goal is achieving 70% time in range each day. However, not everyone starts there, so set small goals. For example, if you increase your time in range by 5% from one week to the next, you will spend an extra hour every day in the target range (between 70-180 mg/dL). Talk to your diabetes care team about strategies to increase time in range.
Reviewed by Anastasia Albanese O’Neill, PhD, 9/11/19
This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.