The Glucose Never Lies®
Welcome to The Glucose Never Lies® Podcast where science meets real-life experience to empower diabetes management.
I’m John Pemberton. I’ve lived with type 1 diabetes since 2008 and have spent nearly 20 years mastering both the science and art of managing it. Through personal experimentation, published research, and my work as a diabetes specialist dietitian, I’ve gained deep insights into what truly makes a difference.
When my son Jude tested positive for type 1 antibodies, I realised that all the knowledge in my head is wasted if I couldn’t communicate it in a way that was clear, actionable, and easy to come back to. So I built The Glucose Never Lies® Education Programme—a free resource designed to teach diabetes management exactly as I’d want people to understand it if they were looking after my son.
After battling a functional motor disorder for many years and recently experiencing a major depressive episode, I was eventually pulled out of that hole by friends, family, and professionals who helped me get back to being me. That experience taught me the power of giving—and this podcast is my way of giving back.
My cohost, Louise Collins, is a highly experienced diabetes nurse with over 20 years in the field. She brings a wealth of knowledge and her superpower is making complex diabetes science accessible and practical for everyday life. She is the best diabetes nurse I have ever worked with, and there have been some good ones! Most importantly, she keeps me in check and on point!
So, if you’re living with diabetes or supporting someone who is, we want to make things easier, clearer, and—importantly—more enjoyable.
We hope you enjoy the content. If you do, please share it with those who may like it too.
Disclaimer: The information shared on The Glucose Never Lies® Podcast is for informational and educational purposes only. While we discuss strategies and insights for diabetes management, this podcast is not a substitute for professional medical advice. Always consult your healthcare team before making any changes to your diabetes care plan.
The Glucose Never Lies®
Episode 11: CGM Accuracy (Part 2): Understanding MARD, 20/20, 40/40, and Error Grids.
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
