The Glucose Never Lies® Podcast
Host John Pemberton — diabetes educator, researcher, and dad living with type 1 since 2008 — explores how to think clearly about type 1 diabetes in the real world.
EACH episode translates current evidence and expert practice into decisions you can use: CGM accuracy and interpretation, getting more from pumps and automated insulin delivery, movement as a glucose tool, nutrition that protects performance and enjoyment, sleep, travel, parties, and sport.
Guests include leading clinicians, researchers, and people with lived experience. Expect respectful challenge, plain language, and practical take-aways.
Note: Educational only. No therapeutic relationship or personal medical advice.
Support | Donate: The Glucose Never Lies® Podcast
☕ Coffee → https://www.buymeacoffee.com/jspfree2s
💙 Donate → https://www.paypal.com/ncp/payment/FGNBMB6KL4YHG
The Glucose Never Lies® Podcast
11: CGM Accuracy (Part 2): Understanding MARD, 20/20, 40/40, and Error Grids.
Suggest guests or get in contact
In this episode of the Glucose Never Lies podcast, hosts John Pemberton and Louise discuss the intricacies of diabetes management, focusing on continuous glucose monitoring (CGM) systems. They explore the importance of CGM accuracy, the standards set by regulatory bodies, and the significance of testing conditions in evaluating these devices. The conversation delves into various metrics used to assess CGM performance, including MARD, 20/20 and 40/40 agreement rates, and highlights the need for robust testing against capillary glucose to ensure effective diabetes management. The episode emphasises the importance of transparency in CGM studies and the future directions for standardizing testing protocols.
takeaways
- CGM systems are crucial for real-time glucose monitoring.
- FDA standards are currently the highest for CGM performance.
- CE marking does not guarantee device accuracy or reliability.
- Testing conditions significantly impact CGM accuracy results.
- The 20/20 standard indicates no risk for insulin dosing decisions.
- The 40/40 metric identifies high-risk readings in CGM data.
- Robust testing against capillary glucose is essential for accuracy.
- Standardization in CGM testing is needed for better diabetes management.
- Transparency in CGM studies is vital for healthcare professionals and patients.
00:00
Introduction to Diabetes Management and Podcast Goals
02:07
Understanding Continuous Glucose Monitoring (CGM) Systems
06:08
Evaluating CGM Accuracy and Performance Standards
10:09
The Importance of Testing Conditions in CGM Studies
14:13
Metrics for Assessing CGM Accuracy
18:03
Comparing CGM Systems Against Capillary Glucose
22:02
Future Directions for CGM Testing and Standards
Key Resources
CGM Series: Assessing CGM Accuracy Performance
Chart for CGM Devices (From May 2025): DSN Forum
Tim Street @ Diabettech
