Maximize Your CGM: Advice from a Diabetes Dietitian
Living with diabetes, whether it's Type 1 (T1D) or Type 2 (T2D), can be challenging, especially when it comes to managing blood sugar levels.
One of the most helpful tools for many individuals is a continuous glucose monitor (CGM). These devices help track blood sugar in real time, better understanding people's daily fluctuations. However, people may face common mistakes and frustrations when using CGMs, and knowing what to avoid can make all the difference.
Here are some tips on using CGMs effectively, avoiding common errors, and ensuring better management of blood sugar levels.
1. Avoid Changing Your Sensor Right Before Bed
For those using CGMs, one major mistake is changing the sensor right before going to sleep. While it may seem like a convenient time, doing so can cause trouble because CGMs, like the Dexcom, require a "warm-up" period of 30 minutes to two hours. This means that if a sensor is changed just before bedtime, it will not provide accurate readings, leaving users "flying blind" during sleep. If blood sugar is high or low during this time, it can lead to dangerous situations without proper monitoring.
2. The First 24–48 Hours Can Be Unpredictable
It’s important to remember that during the first 24 to 48 hours of wearing a new sensor, readings may not be as accurate. A T1D dietitian may recommend calibrating the sensor with a fingerstick test during this period to ensure that the CGM is giving reliable readings. This is especially true for the Dexcom G6 and G7, where the sensor may show blood sugar readings that are either higher or lower than actual values. These discrepancies can impact insulin dosing and lead to unnecessary highs or lows.
While CGMs provide helpful trend data, a diabetes educator or T2D dietitian should emphasize that users shouldn’t rely solely on CGM data, particularly during these first few hours. Calibration ensures the device provides accurate readings during the warm-up phase.
3. Don’t Overthink Sensor Placement
Many people believe that CGM sensors must be placed in body fat for optimal performance. However, the placement of the sensor isn’t as critical as people often think, according to diabetes dietitians. The sensor reads the interstitial fluid, not the fat layer, so it can be placed in a variety of locations. While body fat is generally preferred for insulin pumps, a T1D dietitian can assure patients that CGM sensors work well on areas such as the abdomen or even on the upper arm, where there is less body fat.
4. Don’t Overreact to the Arrows
One of the most frustrating aspects of using a CGM is the constant monitoring of arrows that indicate rising or falling blood sugar. These arrows, often referred to as "trend arrows," show the direction of blood sugar changes. While they can be helpful, overreacting to them can lead to mistakes in insulin dosing. For instance, if blood sugar is rising quickly after a meal, such as after eating pancakes, the immediate instinct might be to correct it by giving more insulin. But this can cause a rebound low later on.
A Type 2 diabetes dietitian or Diabetes Educator would recommend not panicking over every trend arrow. It's important to trust the insulin dose that was taken and allow the body time to adjust. Overcorrecting can lead to blood sugar rollercoasters that are more stressful than helpful.
Wrapping Up
Managing diabetes is not just about monitoring blood sugar, but about understanding the tools available—like continuous glucose monitors—and using them effectively. A T1D dietitian or T2D dietitian can help patients navigate these tools and ensure they are using them to their full potential. Whether you're dealing with Type 1 or Type 2 diabetes, understanding how to avoid common CGM mistakes and when to trust the data can significantly improve blood sugar control and quality of life.
For individuals looking for personalized support, a registered dietitian and certified diabetes educator specializing in diabetes can provide guidance on optimizing CGM use, adjusting insulin, and creating a diet plan that supports stable blood sugar levels. With the right knowledge and approach, living with diabetes doesn't have to feel like a constant struggle.
