JMIR Publications

ABSTRACT

Background:

Glucose variability increases cardiometabolic disease risk. While many factors can influence glucose levels, postprandial glucose responses are the primary driver of glucose variability. Furthermore, affect may directly and indirectly impact glucose variability through its effect on eating behavior. Continuous glucose monitors (CGMs) facilitate the real-time evaluation of blood glucose, and ecological momentary assessment (EMA) can be used to assess affect in real-time. Together, data collected from these sources provide the opportunity to further understand the role of affect in glucose levels.

Objective:

This study aims to: 1) evaluate feasibility and acceptability of using CGMs along with EMA in non-diabetic populations, and 2) examine the bi-directional relationship between affect and glucose in non-diabetic adults with overweight/obesity using CGM and EMA.

Methods:

Eligibility criteria for the study include: 1) age 18-65 years old, 2) BMI > 25, 3) ability to read and write in English, and 4) own a smartphone. Individuals will be excluded if they: 1) have Type 1 or 2 diabetes, or any other condition that requires glucose monitoring, 2) are pregnant, 3) use any medications that has the potential to alter blood glucose levels or interfere with the glucose sensing process, or 3) have a diagnosed gastrointestinal condition or eating disorder. In a 14-day observational study, participants will wear an Abbott Freestyle Libre Pro CGM sensor and will receive mobile phone-based EMA prompts six times per day (randomly within six 2-hour windows between 8am and 8pm) to assess positive and negative affect. Participants will also wear a Fitbit Inspire 2 to continuously monitor physical activity and sleep, which will be included as covariates in the analysis. Multilevel linear regression models will be used to evaluate the acute relationship between glucose level and affect.

Results:

Recruitment started in October 2022 and is expected to be completed in March 2023. As of December 12, 39 participants have been enrolled. A total of 100 participants will be enrolled with a target completion date of March 2023.

Conclusions:

Results of this study will further elucidate the role of affect in glucose variability. By identifying affective states that may lead to glucose excursions, findings from this study could then inform just-in-time behavioral interventions by indicating opportunities for intervention delivery.