Continuous glucose monitors (CGMs) are groundbreaking tools that provide real-time insights into your blood glucose levels, revealing how your dietary choices and lifestyle habits impact your metabolic health. While CGMs are reliable in most scenarios, there are instances where they may give misleading readings, presenting false highs or lows that don’t reflect your actual glucose levels. Understanding and mitigating these sources of error can enhance the accuracy of your data, helping you make informed decisions for your health journey.

Causes of Falsely Elevated Glucose Readings

1. Acetaminophen (Tylenol):

This common over-the-counter pain reliever is used by millions worldwide for various ailments. However, it can lead to falsely elevated glucose readings by causing a chemical reaction in the interstitial fluid, which some CGM sensors may misinterpret as glucose. For those relying heavily on acetaminophen, considering alternative pain relief methods, such as natural remedies, might be wise to avoid skewed readings.

2. Vitamin C Supplementation:

While vitamin C plays a crucial role in maintaining overall health as a powerful antioxidant, excessive intake through supplements can interfere with CGM sensors, leading to inaccurately high glucose readings. To avoid this, focus on obtaining your vitamin C from natural sources, like fruits and vegetables, which also offer additional metabolic health benefits.

Causes of Falsely Lowered Glucose Readings

3. Salicylic Acid:

Commonly found in aspirin and various skincare products, salicylic acid can potentially lower glucose readings by affecting insulin secretion. Although the impact might be minimal, it’s something to consider if you frequently use products containing this compound.

4. Pressure-Induced Sensor Error:

Sleeping or leaning on your CGM sensor can cause ‘compression lows,’ where the pressure leads to false low readings by affecting blood flow or interstitial fluid around the sensor. To minimize this issue, try positioning the sensor on a less pressure-prone area of your body.

Causes of Both Falsely High and Low Readings

5. Extreme Temperatures:

CGMs are designed to function within specific temperature ranges. Exposure to very cold or hot environments can disrupt the sensor’s ability to accurately measure glucose levels. Keeping the sensor within the recommended temperature range is crucial for reliable readings.

6. Certain Prescription Medications:

Drugs like hydroxyurea and others used to treat high blood pressure or respiratory conditions may interfere with CGM readings. If you’re taking any medications, discuss with your healthcare provider how they might affect your glucose monitoring.

7. Sensor Calibration and Lifespan:

New sensors might provide erratic readings during their initial calibration period. Additionally, using a sensor beyond its recommended lifespan can lead to inaccurate data. Adhering to the manufacturer’s guidelines for sensor replacement is essential for maintaining accuracy.

Conclusion

CGMs offer a window into how our bodies respond to different foods, activities, and medications, empowering us with the information needed for optimal metabolic health. By being aware of and adjusting for these potential sources of error, you can ensure your CGM data is as accurate and helpful as possible. Always consult with a healthcare professional when making significant changes to your health routine, especially if you’re concerned about how certain factors may be affecting your glucose monitor readings.