%0 Journal Article %A Brinnae Bent %A Peter J Cho %A April Wittmann %A Connie Thacker %A Srikanth Muppidi %A Michael Snyder %A Matthew J Crowley %A Mark Feinglos %A Jessilyn P Dunn %T Non-invasive wearables for remote monitoring of HbA1c and glucose variability: proof of concept %D 2021 %R 10.1136/bmjdrc-2020-002027 %J BMJ Open Diabetes Research & Care %P e002027 %V 9 %N 1 %X Introduction Diabetes prevalence continues to grow and there remains a significant diagnostic gap in one-third of the US population that has pre-diabetes. Innovative, practical strategies to improve monitoring of glycemic health are desperately needed. In this proof-of-concept study, we explore the relationship between non-invasive wearables and glycemic metrics and demonstrate the feasibility of using non-invasive wearables to estimate glycemic metrics, including hemoglobin A1c (HbA1c) and glucose variability metrics.Research design and methods We recorded over 25 000 measurements from a continuous glucose monitor (CGM) with simultaneous wrist-worn wearable (skin temperature, electrodermal activity, heart rate, and accelerometry sensors) data over 8–10 days in 16 participants with normal glycemic state and pre-diabetes (HbA1c 5.2–6.4). We used data from the wearable to develop machine learning models to predict HbA1c recorded on day 0 and glucose variability calculated from the CGM. We tested the accuracy of the HbA1c model on a retrospective, external validation cohort of 10 additional participants and compared results against CGM-based HbA1c estimation models.Results A total of 250 days of data from 26 participants were collected. Out of the 27 models of glucose variability metrics that we developed using non-invasive wearables, 11 of the models achieved high accuracy (<10% mean average per cent error, MAPE). Our HbA1c estimation model using non-invasive wearables data achieved MAPE of 5.1% on an external validation cohort. The ranking of wearable sensor’s importance in estimating HbA1c was skin temperature (33%), electrodermal activity (28%), accelerometry (25%), and heart rate (14%).Conclusions This study demonstrates the feasibility of using non-invasive wearables to estimate glucose variability metrics and HbA1c for glycemic monitoring and investigates the relationship between non-invasive wearables and the glycemic metrics of glucose variability and HbA1c. The methods used in this study can be used to inform future studies confirming the results of this proof-of-concept study.Data are available upon reasonable request. The data sets generated during and/or analyzed during the current study (the prospective cohort) will be made available 1 year from the date of publication to a public repository that is linked to the Digital Biomarker Discovery Pipeline (DBDP.org)[58]. %U https://drc.bmj.com/content/bmjdrc/9/1/e002027.full.pdf