Factors Predictive of Use and of Benefit From Continuous Glucose Monitoring in Type 1 Diabetes

  1. Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group*
  1. Corresponding author: Roy W. Beck, jdrfapp{at}


OBJECTIVE To evaluate factors associated with successful use of continuous glucose monitoring (CGM) among participants with intensively treated type 1 diabetes in the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Randomized Clinical Trial.

RESEARCH DESIGN AND METHODS The 232 participants randomly assigned to the CGM group (165 with baseline A1C ≥7.0% and 67 with A1C <7.0%) were asked to use CGM on a daily basis. The associations of baseline factors and early CGM use with CGM use ≥6 days/week in the 6th month and with change in A1C from baseline to 6 months were evaluated in regression models.

RESULTS The only baseline factors found to be associated with greater CGM use in month 6 were age ≥25 years (P < 0.001) and more frequent self-reported prestudy blood glucose meter measurements per day (P < 0.001). CGM use and the percentage of CGM glucose values between 71 and 180 mg/dl during the 1st month were predictive of CGM use in month 6 (P < 0.001 and P = 0.002, respectively). More frequent CGM use was associated with a greater reduction in A1C from baseline to 6 months (P < 0.001), a finding present in all age-groups.

CONCLUSIONS After 6 months, near-daily CGM use is more frequent in intensively treated adults with type 1 diabetes than in children and adolescents, although in all age-groups near-daily CGM use is associated with a similar reduction in A1C. Frequency of blood glucose meter monitoring and initial CGM use may help predict the likelihood of long-term CGM benefit in intensively treated patients with type 1 diabetes of all ages.


  • *The list of members of the Writing Committee can be found in the appendix, and a complete list of the members of the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group is available in an online appendix at

  • Clinical trial reg. no. NCT00406133,

  • The study was designed and conducted by the investigators who collectively wrote the manuscript and vouch for the data. The investigators had complete autonomy to analyze and report the trial results. There were no agreements concerning confidentiality of the data between the Juvenile Diabetes Research Foundation and the authors or their institutions. The Jaeb Center for Health Research had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

  • The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

    • Received May 14, 2009.
    • Accepted July 21, 2009.
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  1. Diabetes Care vol. 32 no. 11 1947-1953
  1. Online-Only Appendix
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