Clinical Studies

Landmark JDRF Trial Shows Significant Benefits from CGM Use

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Published in 2008, this landmark randomized, controlled trial conducted by JDRF was the first study to provide clear evidence of improved glycemic outcomes with the use of continuous glucose monitoring (CGM). The study showed that CGM use for at least 6 days a week can lead to significant decreases in A1C, enabling patients to reach their glycemic goals without an increased risk of hypoglycemia.The 322 person, six-month, multi-center randomized trial included both pediatric and adult patients who used either insulin pumps or multiple daily injections to manage their diabetes.



The value of continuous glucose monitoring in the management of type 1 diabetes mellitus has not been determined.


In a multicenter clinical trial, we randomly assigned 322 adults and children who were already receiving intensive therapy for type 1 diabetes to a group with continuous glucose monitoring or to a control group performing home monitoring with a blood glucose meter. All the patients were stratified into three groups according to age and had a glycated hemoglobin level of 7.0 to 10.0%. The primary outcome was the change in the glycated hemoglobin level at 26 weeks.


The changes in glycated hemoglobin levels in the two study groups varied markedly according to age group (P=0.003), with a significant difference among patients 25 years of age or older that favored the continuous-monitoring group (mean difference in change, −0.53%; 95% confidence interval [CI], −0.71 to −0.35; P<0.001). The between-group difference was not significant among those who were 15 to 24 years of age (mean difference, 0.08; 95% CI, −0.17 to 0.33; P=0.52) or among those who were 8 to 14 years of age (mean difference, −0.13; 95% CI, −0.38 to 0.11; P=0.29). Secondary glycated hemoglobin outcomes were better in the continuous-monitoring group than in the control group among the oldest and youngest patients but not among those who were 15 to 24 years of age. The use of continuous glucose monitoring averaged 6.0 or more days per week for 83% of patients 25 years of age or older, 30% of those 15 to 24 years of age, and 50% of those 8 to 14 years of age. The rate of severe hypoglycemia was low and did not differ between the two study groups; however, the trial was not powered to detect such a difference.


Continuous glucose monitoring can be associated with improved glycemic control in adults with type 1 diabetes. Further work is needed to identify barriers to effectiveness of continuous monitoring in children and adolescents. 

Source: JDRF Continuous Glucose Monitoring Study Group. N Engl J Med. 2008;359(14):1464-1476.

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