New Research Published: Rainier Clinical Research Center Contributes to Advances in Continuous Glucose Monitoring
A new publication highlights RCRC research.
Rainier Clinical Research Center (RCRC) is proud to share the publication of new research in Diabetes Therapy examining an important question in diabetes technology: how do everyday factors, including vitamin C supplementation and exercise, affect the accuracy of continuous glucose monitoring (CGM) systems?
Published online on October 9, 2026, the study, “Impact of Ascorbic Acid and Exercise on Accuracy of a Glucose Monitoring System with GDH-FAD Technology in Adult Patients with Type 1 Diabetes Mellitus: A Double-Blinded, Randomized Trial,” includes Tina Mitchell of RCRC among its authors.
The findings offer encouraging evidence about the performance of the iCan i3 continuous glucose monitoring system under the conditions evaluated, contributing to ongoing efforts to improve the reliability of diabetes monitoring technology.
Why CGM Accuracy Matters
Continuous glucose monitors help people living with diabetes track glucose levels and understand how those levels change throughout the day. These insights can support diabetes management by providing information about glucose trends, fluctuations, and time spent within target ranges.
However, CGM accuracy can be affected by factors that vary from one device to another. Vitamin C, also known as ascorbic acid, has been associated with measurement interference in some glucose monitoring systems. Exercise can also affect readings in certain devices, depending on the technology used by their sensors.
Understanding how these factors influence CGM performance is an important part of evaluating new diabetes technologies and the information they provide to patients and healthcare professionals.
Inside the Study
Conducted at RCRC in Renton, Washington, the study evaluated a CGM system that uses glucose dehydrogenase with flavin adenine dinucleotide (GDH-FAD) technology.
Sixteen adults with type 1 diabetes participated in the study. Researchers assessed glucose measurements during a sensor wear period of up to 15 days, comparing CGM readings with blood glucose measurements obtained using a laboratory reference analyzer.
The study reported several important findings that suggest that neither vitamin C administration nor moderate exercise significantly interfered with glucose measurements from the evaluated GDH-FAD-based CGM system under the conditions studied.
These results are relevant because people managing diabetes may encounter both factors in everyday life. Nevertheless, the findings apply to the specific device, dose, exercise conditions, and study population evaluated; additional research is needed to assess performance under a broader range of real-world circumstances.
“Clinical research plays an important role in understanding how medical technologies perform under real-world conditions. We are proud to contribute to research that evaluates continuous glucose monitoring accuracy and helps build the evidence needed to advance diabetes care,” says Tina Mitchell, Clinical Research Nurse at RCRC.
Further research will help clarify how these findings translate to broader patient populations and everyday diabetes management.
Advancing Clinical Research Together
At Rainier Clinical Research Center, participation in clinical studies helps advance the evaluation of medical devices and other healthcare innovations. Published research such as this demonstrates the value of collaboration and rigorous study methods in building the evidence that informs future healthcare developments.
We congratulate all investigators and collaborators involved in this publication and thank the participants whose involvement made the research possible.
Study published in Diabetes Therapy on October 9, 2026.
This article summarizes clinical research findings and is intended for informational purposes only. It does not constitute medical advice or replace guidance from a qualified healthcare professional.