Comparing Real-Time Self-Tracking and Device-Recorded Exercise Data in Subjects with Type 1 Diabetes

Area of Science:

• Endocrinology and Metabolism
• Digital Health and Wearable Technology
• Exercise Physiology

Background:

• Type 1 diabetes (T1D) management requires insulin therapy, medical nutrition therapy, and physical activity.
• Limited real-world studies characterize patient-reported data from logs, activity trackers, and medical devices during exercise.
• Understanding exercise's glycemic impact in T1D necessitates robust data collection methods.

Purpose of the Study:

• To compare data from continuous glucose monitors (CGM), wristband heart rate monitors (WHRM), and a smartphone application (iDECIDE) for tracking exercise behaviors.
• To evaluate the rate of change in glucose levels during exercise as recorded by CGM.
• To assess the concordance between self-reported exercise data and objective monitoring in T1D patients.

Main Methods:

• Participants with T1D on insulin pump therapy tracked exercise using the iDECIDE smartphone app for one month.
• WHRM and CGM devices recorded real-time physiological and glucose data.
• Exercise behaviors (frequency, duration, intensity) and glucose changes were compared between the app, WHRM, and CGM data.

Main Results:

• Tracking exercise frequency and duration with the iDECIDE app showed high agreement with WHRM data (p=0.60 and p=0.45, respectively).
• Concordance for exercise intensity between the app and WHRM was low (Cohen's kappa = 0.2).
• The mean rate of glucose change during exercise was -0.27 mg/(dL*min) and did not significantly differ between data sources or perceived intensity (p=0.21).

Conclusions:

• Patient-reported exercise data from a smartphone app can reliably reflect exercise frequency and duration compared to WHRM.
• Perceived exercise intensity by patients may serve as a practical surrogate for WHRM-tracked intensity in assessing glycemic impact.
• This study highlights the potential of integrating heterogeneous data sources for comprehensive T1D self-management during physical activity.