Previous DirecNet Studies

The Accuracy of Continuous Glucose Monitors in Children with Type 1 Diabetes

Click Here to View Protocol

This study evaluated the accuracy of the CGMS and GWB in 89 children with T1DM between the ages of 3 and 17 yr who were admitted to a Clinical Research Center for 24 hours. Blood sugar values from the CGMS and GWB were compared with “gold standard” blood sugar values that were obtained every 30-60 minutes during the day and night and every 5 min during induced hypo- and hyperglycemia.

 
A Pilot Study to Assess the Accuracy of Continuous Glucose Monitors in Normal Children
 

This study evaluated the accuracy of the CGMS and the GWB in normal children while examining the 24-hour pattern of glucose concentrations. Fifteen healthy children 9-17 years of age (11 boys/4 girls) with no family history of type 1 diabetes and normal BMI were admitted to a Clinical Research Center for 24 hours. Blood sugar values from the CGMS and GWB were compared with “gold standard” blood sugar values that were obtained every 30-60 minutes during the day and night.
 
 
A Pilot Study to Evaluate the GlucoWatch 2 Biographer in the Management of Type 1 Diabetes in Children
 
 
This 3-month pilot study was conducted to assess the feasibility of using PCs in the home for computer-based data acquisition and transmission in a larger 12-month study. Fifteen subjects with T1DM (age range 7.3-17.9 years) were provided with a GW2B and a OneTouch Ultra® meter along with a personal computer and software for downloading glycemic data for each device. The PC was also used weekly to complete a questionnaire regarding hypoglycemia and problems with using the GW2B. Patients were able to view Ultra and GW2B data at any time on the PC. Each week, the data were uploaded to the study coordinating center and made available to the clinical centers on a secure website. Therapeutic changes were based on the downloads, hypoglycemia questionnaires, and telephone contacts with clinical centers. Quality of life, diabetes self-management behaviors and satisfaction with GW2B use were measured periodically.
 
 
A Randomized Trial to Assess the Effectiveness of the GlucoWatch Biographer in the Management of Type 1 Diabetes in Children
 
 
This randomized trial was conducted to assess whether use of the GlucoWatch G2 Biographer (GW2B) with standard glucose monitoring (SGM) lowers HbA1c and the frequency of hypoglycemia in comparison to use of standard blood glucose monitoring alone. Two hundred subjects aged 7 to 18 years were randomized to SGM or SGM plus GW2B use for 6 months. Other than use of the GW2B sensor, both groups were managed as similarly as possible. Subjects in both groups were provided with a PC to download sensor and meter results, to review glucose data as an aid in self-management, and to complete a questionnaire each week.
 
 
The Effect of Exercise on the Development of Hypoglycemia in Children with Type 1 Diabetes
 
 
The main purpose of this study was to find out how often low blood sugar (hypoglycemia) happens during the night after exercise in the late afternoon. The study also looked at whether or not there are any factors that can predict if low blood sugar is going to develop. Blood samples were drawn to measure the blood sugar overnight and during exercise. Blood samples were also drawn to measure hormones to see how they are affected by exercise. Fifty subjects age 10 to 18 years were hospitalized in a research unit of a hospital for two days. During one of the two days (ordered through randomization), a structured exercise protocol was completed in the late afternoon. On the other day, the subjects did not exercise. The subjects’ meals and insulin doses were kept as similar as possible on both days.
 
 
A Pilot Study to Evaluate the Navigator Continuous Glucose Sensor in the Management of Type 1 Diabetes in Children
 
 
This study was done to find out how accurate the Navigator is in children.  It was also done to see if use of the Navigator could improve blood sugar control and help prevent low blood sugar events.  Thirty subjects age 8 to 17 years using insulin pump therapy and thirty subjects using Lantus/multiple daily injection (MDI) therapy were enrolled.  This study has three basic parts: Use of the Navigator at home for one week without being able to see the blood sugar readings; a 24-hour admission to a research unit of the hospital to find out how well the Navigator measures the blood sugar; and then 3 months' use of the Navigator at home as an aid to diabetes care.  At the end of 3 months, the children were given the option to continue use of the Navigator for an additional 3 months or until the end of the study.
 
 
The Effect of Basal Insulin During Exercise on the Development of Hypoglycemia in Children with Type 1 Diabetes
 
 
This study was done to find out if decreasing the insulin that is received during exercise can make low blood sugar (hypoglycemia) less likely. Fifty-five subjects age 8 to 17 years were seen during two outpatient visits each with a 75-minute exercise session in the late afternoon. The basal insulin rate from the subject’s insulin pump was continued during the exercise on one exercise day. On the other exercise day, the basal rate was discontinued at the start of exercise and not restarted until the end of the 45-minute post-exercise observation period. A CGMS continuous glucose monitor was used on both exercise days. Blood samples were collected and blood sugar measurements were performed throughout both visits to determine changes in blood sugar levels during exercise. Blood samples were also drawn to measure hormones to see how they are affected.
 
 
Evaluation of Counter-regulatory Hormone Responses during Hypoglycemia and the Accuracy of Continuous Glucose Monitors in Children with T1DM
 
 
This study was done to compare the glucose level at which counter-regulatory hormone responses occur during hypoglycemia in young children with diabetes, with the glucose level counter regulatory hormone responses that occur in older children with diabetes.  Other objectives of this study include to assess signs and symptoms at different glucose levels of hypoglycemia in younger compared to older children, assess whether there is a difference in counter-regulatory hormone response in each age group, and to examine the accuracy of the Guardian-RT during hypoglycemia in children with type 1 diabetes.  Twenty-five subjects age 3 to less than 7 and 12 to 17 were instructed on use of the Guardian-RT and returned approximately 6 days after the enrollment visit for an 18-hour overnight admission to a research unit.  During the hypoglycemia testing, the child’s blood sugar was dropped slowly and blood samples were taken throughout the testing.  Parents were asked to complete a questionnaire regarding whether their child “felt” or “looked” low throughout the testing.
 
 
A Pilot Study to Evaluate the Safety of Terbutaline in Children with Type 1 Diabetes
 
 
This pilot study of 9 subjects ages 13-18 years was conducted to gain experience with the use of terbutaline in children with type 1 diabetes and to determine if there would be any unexpected side effects from use of the drug. In addition, the study collected data on the accuracy of a pediatric version of the DexCom SEVEN CGM with use of terbutaline.  Subjects wore the CGM at home for one week and then were admitted to a research unit of the hospital overnight to start use of terbutaline (2.5 mg or 3.75 mg dose each night depending on the weight of the subject). Following the first admission, subjects used terbutaline at home for 3-4 weeks before returning for a second hospital admission. During each admission, side effects were monitored by taking blood samples, heart rate and blood pressure.  Blood samples were also collected to assess accuracy of the CGM. Use of terbutaline was discontinued prior to discharge from the second admission and subjects were allowed to continue using the CGM at home for 1-2 weeks at the discretion of the study investigator.
 
This pilot study of 9 subjects ages 13-18 years was conducted to gain experience with the use of terbutaline in children with type 1 diabetes and to determine if there would be any unexpected side effects from use of the drug. In addition, the study collected data on the accuracy of a pediatric version of the DexCom SEVEN CGM with use of terbutaline. Subjects wore the CGM at home for one week and then were admitted to a research unit of the hospital overnight to start use of terbutaline (2.5 mg or 3.75 mg dose each night depending on the weight of the subject). Following the first admission, subjects used terbutaline at home for 3-4 weeks before returning for a second hospital admission. During each admission, side effects were monitored by taking blood samples, heart rate and blood pressure. Blood samples were also collected to assess accuracy of the CGM. Use of terbutaline was discontinued prior to discharge from the second admission and subjects were allowed to continue using the CGM at home for 1-2 weeks at the discretion of the study investigator.
This pilot study of 9 subjects ages 13-18 years was conducted to gain experience with the use of terbutaline in children with type 1 diabetes and to determine if there would be any unexpected side effects from use of the drug. In addition, the study collected data on the accuracy of a pediatric version of the DexCom SEVEN CGM with use of terbutaline. Subjects wore the CGM at home for one week and then were admitted to a research unit of the hospital overnight to start use of terbutaline (2.5 mg or 3.75 mg dose each night depending on the weight of the subject). Following the first admission, subjects used terbutaline at home for 3-4 weeks before returning for a second hospital admission. During each admission, side effects were monitored by taking blood samples, heart rate and blood pressure. Blood samples were also collected to assess accuracy of the CGM. Use of terbutaline was discontinued prior to discharge from the second admission and subjects were allowed to continue using the CGM at home for 1-2 weeks at the discretion of the study investigator.