In Response to the Monitor Trial

A commentary in response to Glucose Self-monitoring in Non-Insulin-Treated Patients With Type 2 Diabetes in Primary Care Settings: A Randomized Trial published in The Journal of the American Medical Association. 

Authors: Jennifer J. Schneider, MD, MS1, Jenna Bollyky, MD1, Dena Bravata, MD, MS2

  1.  Livongo Health, Mountain View, CA
  2.  Stanford University, Primary Care Outcomes Research, Stanford, CA


The recently reported Monitor Trial1 findings suggest that once daily self-monitoring of blood glucose (SMBG) is not associated with improved blood glucose (BG) control or health-related quality of life in patients with non-insulin treated type 2 diabetes in the primary care setting.

We are not surprised by these findings.  Diabetes is a complex condition and multiple factors are well known to affect blood glucose values: diet, exercise, medications, sleep, stress, hormones, etc. Once daily SMBG does not provide a person with diabetes with sufficient information about how these different factors influence their overall BG control. However, structured SMBG, such as before and after meals or exercise, has been shown to effectively reduce HbA1c levels in multiple randomized-controlled trials, presumably by providing feedback about how different activities impact an individual’s blood glucose levels.2-4  Recently reported SMBG study results from Parsons, et al5 demonstrated in a population similar to the Monitor Trial that structured SMBG, specifically before and after a blood glucose altering event (such as a meal), was associated with an A1c decrease of 1.1 points at twelve months compared with 0.3 point reduction in a similar group who did not perform SMBG.

We have seen similar results in our experience with remote monitoring of a similar population of over 7,000 people with non-insulin treated type 2 diabetes through a connected glucose meter in the Livongo for Diabetes Program with self-reported HbA1c of 7.4% at baseline and estimated HbA1c from BG values of 6.8% at 12 months.   The program encourages structured SMBG, gives real-time feedback on individual BG values and overall BG trends directly through the meter, and provides access to coaching from certified diabetes educators.

Structured BG checking enables a person with diabetes to learn how their behaviors impact their blood glucose values. This, combined with highly personalized messages (e.g., your blood glucose is 220 mg/dL an hour after eating, walk for 15 minutes and drink 2 glasses of water) provides people with diabetes the more nuanced information they need to control their condition. The days of once daily BG checking for everyone are behind us. Future studies should not even consider this a standard of care strategy but should instead evaluate the effects of different strategies for structuring SMBG.


1.        Young LA, Buse JB, Weaver MA, et al. Glucose Self-monitoring in Non-Insulin-Treated Patients With Type 2 Diabetes in Primary Care Settings: A Randomized Trial. JAMA Intern Med. June 2017. doi:10.1001/jamainternmed.2017.1233.

2.        Polonsky WH, Fisher L, Schikman CH, et al. Structured Self-Monitoring of Blood Glucose Significantly Reduces A1C Levels in Poorly Controlled, Noninsulin-Treated Type 2 Diabetes. Diabetes Care. 2011;34(2):262-267. doi:10.2337/dc10-1732.

3.        Li C-L, Wu Y-C, Kornelius E, et al. Comparison of Different Models of Structured Self-Monitoring of Blood Glucose in Type 2 Diabetes. Diabetes Technology & Therapeutics. 2016;18(3):171-177. doi:10.1089/dia.2015.0082.

4.        Parsons S, Luzio S, Bain S, et al. Self-monitoring of Blood Glucose in Non-Insulin Treated Type 2 Diabetes (The SMBG Study): study protocol for a randomised controlled trial. BMC Endocr Disord. 2017;17(1):4. doi:10.1186/s12902-017-0154-x.

5.     Self-monitoring of Blood Glucose in Non-Insulin Treated Type 2 Diabetes (The SMBG Study),   Parsons, S, et. Al, ADA 77th Scientific Session, San Diego, CA