This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.
The Onduo virtual diabetes clinic (VDC) for people with type 2 diabetes (T2D) combines a mobile app, remote personalized lifestyle coaching, connected devices, and live video consultations with board-certified endocrinologists for medication management and prescription of real-time continuous glucose monitoring (RT-CGM) devices for intermittent use.
This prospective single-arm study evaluated glycemic outcomes associated with participation in the Onduo VDC for 4 months.
Adults aged ≥18 years with T2D and a baseline glycated hemoglobin (HbA1c) of ≥8% to ≤12% were enrolled from 2 primary care centers from February 2019 to October 2019. Participants were asked to engage at ≥1 time per week with their care team and to participate in a telemedicine consultation with a clinic endocrinologist for diabetes medication review. Participants were asked to use a RT-CGM device and wear six 10-day sensors (total 60 days of sensor wear) intermittently over the course of 4 months. The primary outcome was change in HbA1c at 4 months from baseline. Other endpoints included change in weight and in RT-CGM glycemic metrics, including percent time <70, 70-180, 181-250, and >250 mg/dL. Changes in blood pressure and serum lipids at 4 months were also evaluated.
Participants (n=55) were 57.3 (SD 11.6) years of age, body mass index 33.7 (SD 7.2), and 40% (22/55) female. HbA1c decreased significantly by 1.6% (SD 1%;
Participants in the Onduo VDC experienced significant improvement in HbA1c, increased TIR, decreased time in hyperglycemia, and no increase in hypoglycemia at 4 months. Improvements in other metabolic health parameters including weight and blood pressure were also observed. In conclusion, the Onduo VDC has potential to support people with T2D and their clinicians between office visits by increasing access to specialty care and advanced diabetes technology including RT-CGM.
ClinicalTrials.gov NCT03865381; https://clinicaltrials.gov/ct2/show/NCT03865381
In recent years, there has been a dramatic increase in telehealth programs for the management of diabetes [
There is growing recognition that advanced technology, including continuous glucose monitoring (CGM) devices, can play an essential role in diabetes care for people with type 2 diabetes (T2D), regardless of their treatment regimen [
The primary objective of this prospective single-arm study was to evaluate the change in HbA1c in adults with T2D after 4 months of participation in the Onduo VDC. Additional outcomes included change in glycemic metrics from CGM (mean glucose, coefficient of variation, and percent time <70 mg/dL, 70 to 180 mg/dL [time in range (TIR)], 181 to 250 mg/dL, and >250 mg/dL at 4 months from baseline.Changes in weight, blood pressure (BP), and serum lipids—namely, total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol, cholesterol/HDL ratio, and non-HDL cholesterol—were also evaluated at 4 months from baseline.
Participants were enrolled from 2 primary care networks—Allegheny Health Network, Pittsburgh, PA and Sutter Health Palo Alto Medical Foundation, Palo Alto, CA. Inclusion criteria were as follows: ≥18 years of age or older, confirmed diagnosis of T2D, HbA1c level 8.0% and 12.0%, willingness to use a blood glucose meter and CGM device, and own a smartphone. Exclusion criteria were as follows: use of an insulin pump; pregnant or breastfeeding; malignant cancer in the previous 12 months; any solid organ transplant; end-stage (stage 4 or 5) renal disease or dialysis; liver failure; cystic fibrosis; chronic heart failure (Class C, D); diabetes-related pancreatic failure; current use of a blood thinner; and self-reported adhesive allergy. All participants provided written informed consent. The study protocol and consent forms were approved by the Western Institutional Review Board and registered with ClinicalTrials.gov NCT03865381.
Baseline and final assessments were conducted in-person at the designated study sites including, physical measures, blood draws, and questionnaires. The intervention was conducted remotely through the Onduo VDC.
The Onduo VDC telehealth program for people with T2D has been previously described [
In this study, participants were asked to engage ≥1 time per week with their health coach or care team and to participate in a telemedicine consultation with VDC endocrinologists. All participants were mailed a RT-CGM device—Dexcom G6 (Dexcom)—for intermittent use. Participants were asked to wear six 10-day sensors (total 60 days of sensor wear) intermittently over the course of 4 months. Initial period of CGM device–wearing lasted for 20 days (consisting of 2 sensors worn back to back). Subsequently, the remaining 4 sensors were deployed in a 10-days “on” and 11-days “off” cycle. Sensor glucose data were used by the care team for coaching and monitoring and as an educational feedback loop to assist participants in associating their glucose levels with their diet, lifestyle, and other factors to optimize diabetes self-management. Glucose data were also used by the VDC endocrinologists for medication management. During the 4-month period, additional CGM sensor wear may have been requested by VDC endocrinologists to evaluate the efficacy of medication changes and monitor impact on blood glucose.
A sample size of 60 participants was selected to provide 90% power to detect a 0.5% decrease in HbA1c at 4 months from baseline (primary outcome) using a 2-sided test with α=.05, after assuming 20% loss to follow-up. RT-CGM glycemic metrics, including mean glucose, coefficient of variation, and percent time <70 mg/dL, 70 to 180 mg/dL, 181 to 250 mg/dL, and >250 mg/dL) were calculated from an initial 10-day period within 30 days of enrollment to a 10-day follow-up period >90 days from enrollment, with a data sufficiency requirement of >70% of possible readings. All outcomes were evaluated by paired
A total of 60 participants enrolled in the study, and 92% (55/60) completed the 4-month intervention. Reasons for withdrawal included protocol violations/non-compliance (n=3) and withdrawal of consent (n=2). Out of 55 participants who completed the study, 89% (49/55) had a medication change. Baseline demographic and clinical characteristics of the participants are presented in
Participant demographics at baseline.
Variables | Values | |
Female, n (%) | 22 (40) | |
Age (years) mean (SD) | 57.3 (11.6) | |
Weight (lb) mean (SD) | 218.7 (59.7) | |
BMI,a mean (SD) | 33.7 (7.2) | |
Baseline HbA1c, (%) mean (SD) | 8.9 (1.0) | |
Systolic blood pressure (mm Hg) mean (SD) | 132.1 (15.8) | |
Diastolic blood pressure (mm Hg) mean (SD) | 80.7 (10.4) | |
Total cholesterol (mg/dL) mean (SD) | 168.3 (42.8) | |
HDLb cholesterol (mg/dL) mean (SD) | 40.4 (9.1) | |
LDLc cholesterol (mg/dL) mean (SD) | 100.1 (36.5) | |
Non-HDL cholesterol (mg/dL) mean (SD) | 128.0 (42.70) | |
Total cholesterol/HDL ratio, mean (SD) | 4.4 (1.4) | |
Triglycerides (mg/dL) mean (SD) | 236.7 (194.3) | |
|
||
|
0 | 0 (0) |
|
1 | 6 (11) |
|
2 | 21 (38) |
|
≥3 | 28 (51) |
|
||
|
Alpha glucosidase inhibitor | 1 (2) |
|
Biguanide | 46 (84) |
|
DPP-4d inhibitor | 10 (18) |
|
GLP-1e analogue | 14 (25) |
|
Insulin | 20 (36) |
|
SGLT2f inhibitor | 20 (36) |
|
Sulfonylurea | 30 (55) |
|
Thiazolidinedione | 2 (4) |
|
Lipid-lowering medications | 44 (80) |
aBMI: body mass index.
bHDL: high-density lipoprotein.
cLDL: low-density lipoprotein.
dDPP-4: dipeptidyl peptidase-4.
eGLP-1: glucagon-like peptide-1.
fSGLT2: sodium/glucose cotransporter 2.
HbA1c decreased significantly by 1.6% (SD 1%;
Change in HbA1c at 4 months from baseline. *
Out of 55 participants in the study, 78.2% (43/55) met the criteria of follow-up CGM sensor–wear periods >90 days from baseline. Sensor-wear period was 94.8% (SD 8.2%) of the time specified per protocol (60 days) in this cohort. CGM metrics (n=43) are presented in
Changes in CGM metrics at 4 months from baseline.
Parameter | Baseline |
Follow-up |
Change |
||
Mean glucose (mg/dL) | 169.2 (29.3) | 154.6 (33.0) | –14.6 (27.5) | .001 | |
Coefficient of variation (%) | 24.5 (4.9) | 22.9 (5.5) | –1.6 (4.5) | .02 | |
|
|||||
|
<70 mg/dL | 0.2 (0.4) | 0.3 (0.6) | 0.1 (0.7) | .49 |
|
70 to 180 mg/dL | 65.4 (23.2) | 75.5 (22.7) | 10.2 (20.5) | .002 |
|
181 to 250 mg/dL | 26.5 (14.9) | 19.2 (15.5) | –7.2 (15.4) | .005 |
|
>250 mg/dL | 8.0 (10.9) | 5.0 (11.0) | –3.0 (9.4) | 0.01 |
Change in weight, BP, and serum lipids at 4 months from baseline are presented in
Change in BP and serum lipids at 4 months from baseline.
Parameter | Baseline |
Follow-up |
Change |
|
Weight (lb)a | 217.5 (59.5) | 208.5 (53.7) | –9.0 (10.4) | <.001 |
BMIab | 33.6 (7.2) | 32.2 (6.5) | –1.34 (1.5) | <.001 |
Systolic BPac (mm Hg) | 132.4 (15.8) | 128.0 (16.6) | –4.4 (13.1) | .04 |
Diastolic BP (mm Hg)a | 80.5 (10.5) | 79.8 (10.5) | –0.8 (7.5) | 0.48 |
Total cholesterol (mg/dL) | 168.3 (42.8) | 151.7 (41.1) | –16.6 (46.0) | <.001 |
HDLad cholesterol, (mg/dL) | 40.4 (9.1) | 40.0 (10.9) | –0.4 (7.1) | .90 |
LDLae cholesterol (mg/dL) | 100.1 (36.5) | 93.6 (31.9) | –6.5 (27.5) | .04 |
Total cholesterol/HDL Ratio | 4.4 (1.4) | 3.9 (1.3) | –0.5 (1.4) | .003 |
Triglycerides (mg/dL) | 236.7 (194.30) | 193.0 (163.2) | –43.7 (115.4) | .008 |
aFor n=54 (1 subject did not complete the 4-month assessment at the study site, but submitted results from an external laboratory).
bBMI: body mass index.
cBP: blood pressure.
dHDL: high-density lipoprotein.
eLDL: low-density lipoprotein.
There were no serious adverse events.
In this prospective single-arm trial of the Onduo VDC, adults with T2D and suboptimal glycemic control experienced a statistically significant and clinically meaningful reduction in HbA1c at 4 months. Analysis of RT-CGM metrics demonstrated a significant increase in TIR, decreased time in hyperglycemia, and found no increase in hypoglycemia. Participants also experienced significant decreases in weight, systolic BP, and serum lipids. Delivering RT-CGM devices, incorporating insights from intermittent RT-CGM use, and evaluating glycemic outcomes using RT-CGM data are unique aspects of the overall Onduo VDC care model for people with T2D.
Erhardt et al [
Previous studies of telehealth interventions in individuals with T2D have reported reductions in HbA1c ranging from 0.7% to 2.1% [
Importantly, this is the first telehealth study in which participants with T2D were provided RT-CGM devices and changes in RT-CGM metrics beyond HbA1c were quantified. Providing RT-CGM to participants in the VDC program supports individualized diabetes management in 2 ways. First, it improves self-management by showing participants how specific diet and lifestyle choices impact their blood glucose fluctuations. Second, rich information on glycemic variability that is best derived from CGM data provides information to VDC endocrinologists, pharmacists, nutritionists, CDCES, and health coaches to guide lifestyle and therapeutic interventions.
At a population level, assessing changes in RT-CGM–derived glycemic outcomes supplements HbA1c, offering additional insight into the impact of an intervention on diabetes management. Notably, the mean 10% increase in TIR observed in this study—equivalent to an increase of 2.4 hours per day—is considered a clinically meaningful increase [
Limitations of our study include the sample size, duration of the intervention, and lack of a randomized control arm. It is important to note that some of the observed decrease in HbA1c may be attributed to regression to the mean. Further studies are planned.
This prospective clinical trial of the Onduo VDC demonstrated improvements in glycemic outcomes in adults with suboptimally controlled T2D. Improvements in risk factors for diabetes complications, including weight, BP, and serum lipids were also observed.
body mass index
blood pressure
Certified Diabetes Care and Education Specialist
continuous glucose monitoring
glycated hemoglobin
high-density lipoprotein
low-density lipoprotein
randomized controlled trial
real-time continuous glucose monitoring
type 2 diabetes
time in range
virtual diabetes clinic
The authors thank the study participants and Onduo clinical team, including the care leads and certified diabetes educators. We would like to thank John Schmucker and Anne Vermeulen for their leadership. We thank the staff at the participating research centers, particularly, Ashley Wilferd and the staff of the Allegheny Singer Research Institute of the Allegheny Health Network, Pittsburgh, PA; Elizabeth Mesghina and the staff of Sutter Health; and Palo Alto Medical Foundation Research Institute, Palo Alto, CA. We appreciate the efforts of the research and clinical teams at Verily Life Sciences, including Riddhi Kapoor, Maryam Yaghini, and Karina Brennecke. Funding for the study was provided by Onduo LLC, Newton, MA. Some of these data were presented at the 80th Scientific Sessions of the American Diabetes Association, A Virtual Experience, June 12-16, 2020.
All authors contributed to the review of the report and approved the final version for submission. FRC, DME, and RJR contributed to the acquisition of data and all authors contributed to the interpretation of data. JEL developed the first draft of the manuscript. All authors contributed with a critical revision of the first and subsequent manuscript versions. RFD, CMK, AAL, ARM, DPM, HZ, and SR contributed to the study design. ARM is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
ARM has received consulting fees from Onduo LLC. RFD and JEL are employees of Onduo LLC, a joint venture of Verily Life Sciences and Sanofi. CMK, AAL, HZ, and DPM are employees and shareholders of Verily Life Sciences. SR was an employee of Verily Life Sciences at the time the work was completed. DME is an employee of Onduo Professionals, PC, which provides clinical services to Onduo LLC. RJR and FRC report no conflicts of interest.