A new study, funded by the Juvenile Diabetes Research Foundation (JDRF) and published online this month in The New England Journal of Medicine, has found that using a continuous glucose monitoring (CGM) system can lower blood glucose levels significantly in six months in adults with Type 1 diabetes.
The study enrolled 322 children, teenagers, and adults with Type 1 diabetes, randomly assigning half the participants to use CGM devices. The CGM group members were instructed to verify glucose levels with a blood glucose check before making treatment decisions, while the people who did not receive CGM devices (the “control group”) were given blood glucose meters and test strips and instructed to check their blood glucose levels at least four times a day.
At the end of six months, the adults (ages 25 to 72 years old) who were assigned to use continuous glucose monitors had a reduction of about half a percentage point in their HbA1c levels—a significant change compared to the control group, which saw a slight increase in HbA1c levels. This improvement was achieved without a difference in hypoglycemia, or low blood glucose levels, between the two groups.
Statistically significant reductions in HbA1c were not seen in the two groups of younger people (ages 8 to 14 years old and 15 to 24 years old) who participated in the study. However, the people in these age groups used their CGM devices only 50% of the time or less. The adult group, which did see a significant drop in HbA1c levels, used the device more than 85% of the time. In all age groups, people who used the CGM device at least six days a week lowered their HbA1c levels.
The researchers concluded that “continuous glucose monitoring improves glycated hemoglobin [HbA1c] levels and may enhance the management of Type 1 diabetes in adults who have the motivation to use this technology and the capability to incorporate it into their own daily diabetes management.”
This study may play in important roll in getting health insurance companies to reimburse the cost of CGM devices for adults with Type 1 diabetes. CGM coverage is currently considered on a “case by case” basis by most insurance companies.
There are currently four CGM systems on the market in the United States: the DexCom Seven, the FreeStyle Navigator, the Medtronic MiniMed Guardian REAL-Time System, and the Medtronic MiniMed Paradigm REAL-Time System, in which the receiver is combined with an insulin pump. The Seven, the Navigator, and the Paradigm systems were all used in this new study.
You can find links to more information about the “CGM Anti-Denial Campaign,” the JDRF’s guide to getting case-by-case coverage for a CGM, and more in our recent entry “What We’re Reading: CGMS Denial Week.” And you can find the new study itself online here.