Abstract A17: An innovative physical activity intervention in overweight and obese adults using continuous glucose monitor
Authors: Liao Yue , Miller Christopher J. , Urbauer Diana L. , Bevers Therese B. , Hawk Ernest , Basen-Engquist Karen M. , Schembre Susan M. 
Published: June 2022

Abstract
Introduction: Regular physical activity (PA) lowers the risk of endometrial, breast, and colorectal cancer. However, nearly half of American adults are not sufficiently active. The physical inactivity rate is even higher among the overweight and obese population, which, in combination with the unfavorable effect of excess body weight, puts this population at a greater risk for cancer. Advancements in wearable sensor technology provide opportunities for personalized approaches to increase motivation to be active. The current pilot study used continuous glucose monitors (CGM) to demonstrate the immediate, physiologic benefits of PA.
Methods: Insufficiently active (&lt;150 mins of moderate intensity PA per week) overweight and obese (body mass index &gt;= 25 kg/m2) adults (18-65 years old) without diabetes are being recruited to participate in this pilot intervention. Upon enrollment, participants go through a one-on-one PA education session that includes a discussion about the health benefits of recommended PA levels, demonstration of the acute effect of PA on daily glucose patterns using a web-based glucose simulator, calculation of personal heart rate zones for moderate intensity PA, and development of an exercise plan. After the education session, participants are given a Fitbit Alta HR wristband and are instructed to wear it over the next 10 days. Participants are also given a Freestyle Libre CGM, which consists of a sensor and a reader. The sensor is inserted into the back of the upper arm to collect interstitial glucose data every 15 minutes for 10 days after activation. The reader displays current glucose readings and a graph of the 8 previous hours of glucose data upon scanning the sensor. Participants are instructed to scan the sensor at least 4 times a day and are encouraged to achieve at least 150 minutes of moderate-intensity PA each week. At the end of the self-monitoring period, participants return their Fitbit and have their CGM sensor removed.
Results: Thus far, 10 of 20 participants have enrolled in and completed the study. These participants have been 100% female, 70% obese, and 20% Hispanic with a mean age of 41.5 (SD = 8.6) years old. On average, participants scanned their sensor 6 times each day and wore the Fitbit for all 10 days. On average, participants highly rated each component of the education session (on a 5-point scale) for improving their PA knowledge (mean = 4.4), increasing their PA motivation (mean = 4.4), and providing personally relevant information (mean = 4.6). Participants also reported a very positive experience wearing the CGM, with mean ratings (on a 5-point scale) of 4.8 for usability, 4.6 for convenience, 4.9 for value, 4.9 for relevance, and 4.7 for motivating.
Conclusion: These preliminary data suggest that using a CGM to motivate PA among nondiabetic adults is feasible and acceptable. Future research will be conducted to examine the effect a CGM-based PA intervention has on changing PA behavior.
Citation Format: Yue Liao, Christopher J. Miller, Diana L. Urbauer, Therese B. Bevers, Ernest Hawk, Karen M. Basen-Engquist, Susan M. Schembre. An innovative physical activity intervention in overweight and obese adults using continuous glucose monitor [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A17.