Benefits of continuous glucose monitoring sustained after one year

However, children and adolescents were less likely to use continuous glucose monitoring on a daily basis compared with adults.

After one year of continuous glucose monitoring, HbA1c was sustained at 6.4% in patients with type 1 diabetes who had HbA1c <7% at baseline.

Researchers from the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group conducted two studies to evaluate the long-term effects of continuous glucose monitoring and the factors associated with successful use. The results of both studies were published in Diabetes Care.

In the first study, the researchers evaluated 83 patients aged 25 or older who had type 1 diabetes and used continuous glucose monitoring. At one year, the patients reported using continuous glucose monitoring for a median of 6.8 days per week, and use did not vary based on baseline HbA1c level. In patients with HbA1c ≥7% at baseline (n=49), mean change in HbA1c at one year was –0.4% (P<.001). Throughout the course of the one-year study, HbA1c level remained at 6.4% for patients with baseline HbA1c <7% (n=34).

The researchers reported 21.8 severe hypoglycemia events per 100 person-years in the first six months and 7.1 events per 100 person-years in the last six months. They also observed an increase in the amount of time per day when glucose levels were in the range of 71 mg/dL to 180 mg/dL (P=.02).

Predicting successful use

In the second study, the researchers evaluated 232 patients who had been randomly assigned to the continuous glucose monitoring group as part of the JDRF Continuous Glucose Monitoring Randomized Clinical Trial. At baseline, 165 patients had HbA1c ≥7% and 67 had HbA1c <7%.

At six months, the researchers found that near-daily continuous glucose monitoring use was more frequent in intensively treated adults with type 1 diabetes as opposed to children and adolescents. Eighty-three percent of patients aged 25 or older used continuous glucose monitoring for six or more days per week compared with 30% of patients aged 15 to 24 and 50% of patients aged 8 to 14 (P<.001).

Greater continuous glucose monitoring use (consistent use for six or more days) in the sixth month was also predicted by more frequently self-reporting blood glucose meter measurements before the study (P<.001), continuous glucose monitoring in the first month (P<.001) and the percentage of glucose values between 71 mg/dL and 180 mg/dL in the first month (P=.002).

In all age groups, more frequent use of continuous glucose monitoring was associated with a greater reduction in HbA1c at six months (P<.001).

The researchers noted that these results should be interpreted while keeping in mind that all patients were undergoing intensive treatment with an insulin pump or multiple daily injections before entering the trial.

The Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. Diabetes Care. 2009;32:1947-1953.
The Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. Diabetes Care. 2009;32:2047-2049.