Daily glucose pattern and physical activity levels in cancer survivors: preliminary results from remote monitoring
Authors: Liao Yue , Pavuluri Devika , Chang Keng-Yu , Liu Zhaoli , Hwang Chueh-Lung , Fadel Paul , Brothers R. Matthew 
Published: May 2024

Background: Cancer survivors have elevated risk for type 2 diabetes. Increasing physical activity improves glucose control. However, this evidence is majorly based on blood glucose metrics (e.g., glucose or hemoglobin A1c) at a single point in time. Little is known about the effect of physical activity on blood glucose changes throughout a day in cancer survivors. Thus, we tested the hypothesis that higher physical activity levels is associated with a more favorable daily glucose pattern in cancer survivors in free-living settings. Methods: This is a preliminary analysis of an ongoing randomized controlled trial (Project KNOWN) to examine the effect of physical activity on daily glucose pattern via continuous remote monitoring. A total of 11 cancer survivors were included in this analysis (90% female, 90% white, average age 62.5 years [range 44-76 yr], 67% obese, and 75% hypertension). Participants wore a wrist-worn accelerometer (for daily steps) and a blinded continuous glucose monitor (CGM; for daily glucose averages [interstitial glucose was measured at every 15 minutes] and daily frequency of glucose spikes [defined as glucose level >140 mg/dL]) for two weeks. Multilevel regression model was used to account for multiple observations within each individual and to separate the within-person (WP) and between-person (BP) effects. The WP effect represents deviation from one’s own mean on any given day, and the BP effect represents the individual mean deviation from the study sample mean. To explore moderating effect on the relationship between physical activity and daily glucose, inflammatory biomarkers, blood lipids, blood pressure and body fatness (DEXA scan) were measured. Results: At the WP level, participants with elevated (>4 mg/L) systemic C-reactive protein (marker of inflammatory status), on the day when they had higher-than-usual step count, their glucose average was also lower than their usual level ( p=0.04). At the BP level, daily steps were negatively associated with daily frequency of glucose spikes in participants with less severe hypertension, lower % gynoid fat, and higher android/gynoid ratio than others in the study sample (all p<0.05). Further, daily steps were negatively associated with daily glucose average in participants with higher trunk-to-total fat ratio than others (p<0.05). Discussion: This preliminary study demonstrated the use of data from wearable sensors to analyze intra- and inter-person variability in daily glucose patterns in cancer survivors. Results suggested the impact of physical activity on daily glucose patterns might differ by a person’s physiological status. Future research can further characterize meaningful daily glucose dynamics from CGM data in cancer survivors to better understand how physical activity may have downstream effect on their health outcomes. American Institute for Cancer Research. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.