The Pros + Cons of CGM Data for Diabetes Management


The data you gain from diabetes technology—like continuous glucose monitors (CGMs)—can be so helpful, but too much data can drive you crazy. These are some of the top ways that accessing diabetes CGM data helps and hinders people with type 1 and type 2 diabetes.

How CGM data helps diabetes management

Here are a few ways the data you gain from a CGM can help you in the day-to-day work of blood sugar management.

Predictable blood sugar levels

Wearing a continuous glucose monitor (CGM) means seeing when your blood sugar levels are rising or falling at any given moment. (You can also set alarms to inform you!) The ability to predict oncoming lows and highs means you are likely safer and more prepared throughout the day with diabetes.

Alerts and predicting fluctuations make it easier to exercise, manage insulin during and after eating, help you get more sleep and simply make it through each day with less worry. On the other hand, blood sugar readings with blood glucose meters (BGM) simply give you a momentary snapshot of what’s happening. A BGM simply doesn’t provide the same insights. 

Being able to anticipate whether your blood glucose levels are falling or rising can help prevent severe highs and lows.

Easier basal insulin self-adjustments

The information you gain from CGM data can make fine-tuning your insulin doses much easier. Especially since most people on multiple daily injections take their basal insulin at night, it’s important to make those changes carefully. By wearing a CGM, you can determine whether your blood sugar levels are rising, falling, or following a (reasonably) straight line at night.

CGM data can help you make more informed decisions regarding your diabetes management instead of guessing whether certain foods or activities significantly impact your basal insulin. For example, CGM data can help you find the answers to questions like:

  • How does exercising one hour versus three hours before bed affect your blood sugar levels? 
  • How does eating before bed affect your blood glucose levels? Are you getting enough insulin (or too much) with the meals you eat before bed?
  • How well are my overnight basal insulin doses helping me wake up in my goal range by morning?

Note: Talk to your healthcare team whenever you’re considering adjusting your insulin dosing regimen.

Safer blood sugar corrections

By wearing a CGM, you can anticipate whether your blood sugar levels are rising or falling. These insights are safer than getting a snapshot reading on a BGM. 

For example: Imagine you had a reading on your BGM of 11.1 mmol/L200 mg/dL and gave two units of insulin to correct for it. Unbeknownst to you, your blood sugar was already falling from the insulin you took a couple of hours ago. Without the data that tells you what direction your 200 mg/dL blood sugar is headed in, you increase your risk of severe hypoglycemia by taking additional unneeded insulin. 

CGMs can make blood sugar corrections safer for people with diabetes. Many CGMs also allow you to log the timing of your insulin doses if they’re not already automatically tracking it. That data can help prevent over-correcting highs and over-treating lows. 

Reach your A1c goals

While diabetes checkups and management should go far beyond A1c, that test result is still an important part. A1c results give you a general idea of what’s going on, but a CGM helps to fill in the real details of the big picture. 

By wearing a CGM, you can identify trends in your blood sugar data, which can help you determine how your body reacts to insulin, food, exercise, sleep, etc.

CGMs—like Dexcom and Freestyle Libre—give you access to time-in-range reports that can help determine whether you are likely to reach your A1c goals and where you can make adjustments with your doctor.

Looping improves data quality, helping you be less hands-on

You can reap the benefits of looping by integrating an insulin pump into your diabetes management plan and using a CGM. (Looping is a do-it-yourself alternative, off-label use of diabetes devices that is not FDA-approved. Looping automates insulin delivery and is more flexible for people with diabetes than currently approved systems.)

Looping can automate many insulin decisions you usually make through a brilliant set of algorithms that analyze and predict your blood sugar levels and insulin needs. 

Every looping system works slightly differently, but the results are similarly positive for people with diabetes! Many people with diabetes who loop their tech celebrate how it helps them be less hands-on with their management and gain access to improved data quality.

Data improves autonomy

Parents of children with diabetes in our community have shared that having access to data reduces the assistance their children need from their school nurses and teachers. Data access can help children and adults become more independent and confident in diabetes management.

For a parent, the CGM alerts are a tremendous stress relief when your child is sleeping, at school, at a sleepover and exercising. CGM technology can significantly change the experience of diabetes management for both the child and parents.

Data-sharing helps you feel less alone while managing T2D or T1D

Data-sharing can help people with type 2 and type 1 diabetes feel less alone in their management journeys. No one with diabetes should feel like they don’t have a support system. 

CGMs like Freestyle Libre and Dexcom both have data-sharing apps that let you easily share with friends and family. CGM data-sharing has many benefits—it can help your close friends and family see what you go through daily, help you in an emergency, help you feel assured that someone you love is watching over you, and more.

Sharing your CGM data with the people closest to you (spouses, siblings, best friends, parents, etc.) can be great so long as these people know that you are the decision-maker and all of the data being shared with them is a data point! 

Data-sharing should only add to the support you feel from your loved ones while managing type 2 or type 1 diabetes.

How CGM data hinders diabetes management

Sometimes, there is such a thing as too much technology. Here are a few ways CGM data can get in the way of living with diabetes.

Annoying alarms

As much as you might rely on CGM alarms for your safety, they can be annoying day-in and day-out. Yes, the annoying sounds help you address fluctuating blood sugar levels, but if your blood sugar is stubbornly high for a few hours, the incessant alarm can make you want to throw your CGM against a wall!

While turning your CGM alarms off is an option, you might forget to turn them back on and miss the life-saving alerts when you need them most. Alarms can also make you impatient about correcting your blood sugar levels, leading to overcorrecting and experiencing severe highs and lows.

Some people use the Libre 14-Day sensor—which doesn’t alarm because it isn’t technically continuous. Instead, you can scan the sensor on your arm as often per day as you need to, but you miss out on the safety that comes with alarms.

With everything people with diabetes have to manage, alarms can be a tipping point on the frustration scale!

People with type 2 diabetes often struggle to gain access

Unfortunately, it is often more challenging for people with type 2 diabetes to prove they need a CGM. Most insurance companies require that a person is taking multiple daily injections of insulin before they will cover the expense of CGM technology.

Getting insurance approvals on leading diabetes tech can be exhausting, and a lack of access to technology and its data sets is a massive community problem! Many insurance companies deny people with type 2 diabetes or make it overly complicated to get approved. 

Sensor allergies

While this isn’t necessarily data-related, we had to sneak it in here because this is another fundamental problem for people with diabetes! Some people with diabetes are allergic to CGM sensor adhesives. This allergy means they have no other options but to use blood glucose meters, which are data-limited by comparison.

Constant data access can lead to diabetes distress

Though it’s a privilege to access CGM data, having too much access can be stressful and lead to excessive diabetes management. 

If you know the blood sugar number is always there, you may feel more inclined to look, increasing the time you think about diabetes daily—scanning your sensor as often as possible.

Everyone needs a break from data sometimes. Over-stimulation can lead to heightened diabetes distress, anxiety and even burnout—otherwise known as data fatigue! Limiting how much you look at your data can do wonders for your mental health.

The bottom line: what works for you is what matters

How you feel about your CGM data may vary by day (or even by the hour). That’s okay! What matters most in your diabetes management plan is finding what works for you. 

Educational content related to the pros and cons of CGM data for diabetes management is made possible with support from Abbott, makers of the Freestyle Libre 2, an active partner of Beyond Type 2 at the time of publication. ​Editorial control rests solely on Beyond Type 2.

WRITTEN BY Julia Flaherty, POSTED 06/16/22, UPDATED 01/07/23

Julia Flaherty is a published children’s book author, writer, editor, award-winning digital marketer, content creator and diabetes advocate. Find Julia’s first book, “Rosie Becomes a Warrior.” Julia finds therapy in building connections within the diabetes community. Being able to contribute to its progress brings her joy. She loves connecting with the diabetes communities, being creative and storytelling. You will find Julia hiking, traveling, working on her next book, or diving into a new art project in her free time. Connect with Julia on LinkedIn, Instagram, or Twitter.