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Current DirecNet Studies
A
Pilot Study to Evaluate the Navigator Continuous Glucose Sensor in the
Management of Type 1 Diabetes in Children
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Continuous blood sugar monitoring could be helpful in
trying to reduce the number of times the blood sugar is too high or too
low. We are conducting a study to
evaluate the FreeStyle Navigator™ Continuous Glucose Monitor
(Navigator) made by Abbott Diabetes Care.
The Navigator has a small
sensor that is inserted just underneath the skin and is worn for up to 120
hours. The sensor is then replaced. The sensor measures the blood sugar every 60 seconds and
displays the results on a wireless receiver that is the size of a pager
(beeper). The wireless receiver can be
worn on a belt or carried in a pocket or purse. The sensor requires calibration values to be entered 3
times during the first 24 hours of use.
The values are entered directly into the Navigator which has a home
glucose meter called the FreeStyle® built into the unit. The Navigator is considered an investigational device because it has not
yet been approved by the Food and Drug Administration (FDA). This study is being done to find out how accurate the
Navigator is in children. It is also being
done to see if use of the Navigator can improve blood sugar control and help
prevent low blood sugar events. 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. |
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To take part in the study, subjects will need to: |
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1. Be less than 18 years old 2. Have type 1 diabetes 3. Have used an insulin pump that can be downloaded or Lantus with MDI of a short-acting insulin (e.g. Humalog or Novolog) for at least 6 months 4. Have a computer at home with internet and e-mail access 5. Not have plans to move out of this area in the next 3 months 6. Be willing to use only the Freestyle meter built into the Navigator for blood sugar testing 7. Be
willing to follow the procedures that will be described in the next section. |
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Study Procedures |
1.
On the day of
enrollment, a hemoglobin A1c is obtained, psychosocial questionnaires are
completed, and instructions are given for use of the Navigator sensor. The study personnel will supervise the
subject or parent inserting the Navigator sensor in the clinic and will
instruct the subject or parent to insert a second sensor at home in 5
days. To obtain a baseline assessment
of glycemic variability, the Navigator used during the first week will be
blinded so subjects will not be able to view the data from the sensor. The
subject will be instructed to complete at least four glucose measurements a
day using the Freestyle meter built into the device.
2. Subjects using insulin pump therapy will return for a 24-hour CRC admission approximately one week (7-12 days) after the enrollment visit.
3. Subjects using Lantus with MDI therapy will return for a Baseline Visit approximately one week (7-12 days) after the enrollment visit.
4. Each subject will be provided with the instructions for downloading the Navigator. 5. A follow-up visit will be performed at 1, 3, 7, and 13 weeks after the CRC admission or Baseline Visit. The visit windows will be +3 days at weeks 1, 3, and 7 and +1 week for week 13. ·
At
each visit, the Navigator will be downloaded, diabetes management will be
reviewed, and compliance with use of the algorithms will be assessed. A study
investigator will review the glucose data generated by the Navigator, trends
and, in conjunction with the nurse coordinator make treatment
recommendations. This will continue until enough collective experience has
developed for the nurse coordinator to make the insulin adjustments more
autonomously. ·
At
each visit, the subject’s BG will be tested on his/her Freestyle meter
and a Freestyle meter at the clinic to assess the accuracy of the home meters
over time. ·
At
the 3, 7, and 13-week visits, a psychosocial questionnaire regarding the
frequency and convenience of use of the algorithms will be administered. ·
At
the 7-week visit, HbA1c will be measured ·
At
the 13-week visit, HbA1c will be measured and psychosocial questionnaires
will be administered. 6. Phone contacts will be made with the subjects after 3 days (+1 day), then at 2, 4, 8, and 10 weeks (+3 days) following the CRC admission or Baseline Visit to review their diabetes management and assess compliance with use of the algorithms. Phone contacts will also involve collection of diet data as well as any illnesses, stressful events, and menstrual cycle data for females. 7. At the 13-week visit, subjects who are interested in continuing to use the Navigator will continue in the study for another 13 weeks. Subjects who are not interested will be discontinued from the study. 8. Subjects continuing in the study will be provided with additional sensors and instructed to use them as frequently as they would like. Subjects will also be instructed to continue using the algorithms for diabetes management. · At the 26-week visit, psychosocial questionnaires regarding the satisfaction with the Navigator as well as the algorithms will be administered, frequency of use of the sensors and continued compliance with use of algorithms will be assessed, and HbA1c will be measured. · At the 26-week visit, subjects will be given the choice to continue in the study until the device is approved by the FDA or until Abbott Diabetes Care can no longer provide supplies for the study. Subjects who agree to continue in the study will sign an addendum to the informed consent at the 26-week visit. o Subjects who continue in the study will return to the clinic every 3 months for a follow-up visit. The same procedures completed during the 26-week visit will be completed at each subsequent visit. |
Nocturnal Hypoglycemia Prevention
Ancillary Study
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Low blood sugar at night (called nocturnal hypoglycemia), can often happen without symptoms and can last for a long time. Doctors often suggest that patients take a bedtime snack to try to prevent low blood sugar at night from happening, but it is not known what type of snack is best to take. We are conducting an ancillary study to evaluate how two different types of snacks affect how often the blood sugar is too low overnight. One snack will be potato chips and the other will be honey wheat pretzels. The snacks will be provided by the study. |
Subjects participating in the
Navigator Pilot Study who have completed the 26-week visit are eligible to
participate in this optional ancillary study.
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Study Procedures
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When a child enters the study, the following
will be done: 1. The child will be asked about his or her
diabetes management including overnight basal rates, correction doses, and
bolus doses to cover a bedtime snack and whether these change depending on
how active the day was. 2. The child will be asked to wear 3 Navigator
sensors to get at least 12 nights of readings during a three week period. 3. The child may be taught to use the
accelerometer. This is a device that
measures the amount of movement the child has. It is about 1.75 inches long and about 1.75
inches wide and is strapped to the skin around the waist. 4. The child will be given instructions on how to
use the study website to complete a questionnaire to obtain the type of
bedtime snack to have. The amount of
snack and the insulin dose to cover the bedtime snack will be based on the
child’s usual diabetes management.
On six of the nights the child will be asked to eat potato chips and
on the other six nights, the child will be asked to eat pretzels. The order of the snacks will be chosen at
random by the computer. If a drink is
needed, the child will be asked to drink only water with the bedtime
snack. The child will also be asked to
not have any caffeine after dinner each night. 5.
The child
will be asked to do the following before returning for a clinic visit about 3
weeks later: Ø Wear three Navigator sensors to get a total of at least 12 nights of blood sugar readings Ø Enter a meal marker event into the Navigator each time he or she has a meal or snack Ø Enter an exercise marker event into the Navigator each time he or she exercises Ø Complete a short questionnaire on the study website each of the 12 nights when the Navigator is worn to find out the type of bedtime snack to have Ø The child may also be asked to wear an accelerometer at all times (day and night) when the Navigator is worn Follow-up Visit After using the Navigator and completing the
questionnaire on the website for 12 nights, the child will return to the
clinic for the follow-up visit. 1. The Navigator and the accelerometer (if used)
will be connected to a computer so that the data can be saved. Ø
If the
child does not have at least 12 nights with at least 5 hours of Navigator
data in the monitor and a completed website questionnaire, he or she will be
given additional snacks and asked to wear another sensor and to come back in
another week. 2. Once the child has at least 12 nights with at
least 5 hours of Navigator data and a completed website questionnaire, the
information will be reviewed with the parent and child. |