Continuous Glucose Monitor in Children With Poorly Controlled Diabetes

iPro Continuous Glucose Monitor in Children With Poorly Controlled Diabetes: A 6-Month, Randomized, Interventional Pilot Study

The purpose of this study is to determine if the use of continuous glucose monitoring in a practical outpatient clinic setting in children with poorly controlled diabetes will lead to improved blood sugar control.

The trial was designed as a six month, randomized, prospective, interventional pilot study of children with uncontrolled (HgbA1c > 8.5%) diabetes who were between the ages of 7-17 years of age. The purpose of the study was to determine the effect in glycemic control as measured by HgbA1c with use of iPro™ CGM at regularly scheduled clinic appointments. Recruitment for this study was limited to patients at the University of Texas Health Science Center in San Antonio Pediatric Diabetes Clinic from May 2011 to March 2013. Subjects were randomized into Group1 or Group 2 using sequentially numbered, opaque sealed envelopes (SNOSE).

All subjects had point-of-care HgbA1c (standard of care) and CGM data collected at time points 0, 3 months, and 6 months. After a regularly scheduled clinic appointment, all subjects and families at time 0 were counseled by a registered dietician regarding carbohydrate counting with a focus on minimizing errors in carbohydrate estimation, as is standard of care for patients with poorly controlled diabetes in our clinic. At time 0, subjects in both Group 1 and 2 had CGM placement after meeting with the dietician. Group 1 subjects were blinded to the first CGM data, meaning that they did not review the CGM download data. Group 2 was scheduled to return to clinic within 2 weeks of placement to meet with a pediatric endocrinologist involved in the study to interpret the CGM results and make adjustments to insulin regimen if appropriate. Both Groups 1 and 2 were not blinded to CGM data at 3 months and 6 months. Again, the CGM was placed after their regularly scheduled diabetes clinic appointments and all families returned within 2 weeks of these visits to meet with the pediatric endocrinologist to interpret the data and adjust the insulin regimen if necessary.

The iPro™ CGM was worn for a minimum of 48 hours (2 days), maximum 96 hours (4 days). Participants were instructed to complete a minimum of 4 SMBG records daily while wearing the iPro™ CGM for system calibration purposes. Subjects documented SMBGs, meal times, carbohydrate intake, insulin doses, exercise, and any hypoglycemic symptoms in a log book for correlation to CGM data.

Inclusion Criteria:

1. Clinical diagnosis of diabetes for at least 6 months, type 1 or type 2 diabetes.
2. Treated at UT Health Science Center pediatric diabetes clinic for at least the previous 3 months.
3. HgbA1c >8.5% (equivalent to average BG of >205 mg/dL for past three months).
4. Supportive family with willingness to self monitoring blood glucose values at least 4 times per day during study.
5. Supportive family with willingness to participate in continuous glucose monitoring (CGM) for at least 48 hours including self monitoring blood glucose values at least 4 times per day, documenting meals, carbohydrates eaten, insulin dose given, exercise, and hypoglycemic symptoms.
6. Attend proposed clinic, nutritional, and CGM follow up visits.
7. Pump or multiple daily injection (MDI) insulin therapy (3-4 injections minimum daily). If on pump, on pump for at least the past 3 months. Current insulin regimen involves basal/ bolus therapy with no plans to switch the modality of insulin administration during the study (e.g., injection user switching to a pump, pump user switching to injections).
8. Hypoglycemic unawareness.
9. English or Spanish primary language.

Exclusion Criteria:

1. Medications known to affect glycemic control (oral steroids, growth hormone, psychotropics).
2. Documented concomitant chronic disease known to affect glycemic control.
3. 3 or more incidents in the last 12 months of severe hypoglycemia with documented blood glucose below 50mg/dL (if possible), resulting in unconsciousness, hospitalization or third party assistance, where recovery follows treatment with glucose or glucagon or similar.
4. 3 or more incidents in the last 12 months of diabetic ketoacidosis (DKA).
5. Reported alcohol or drug abuse.
6. Documented cutaneous allergy to latex products.
7. Documented eating disorders or morbid obesity as assessed by the investigator.
8. Any other medical, social or psychological condition that, in the investigator's opinion, makes the patient unable to comply with the study protocol and all study procedures.
9. Home use of CGM in the past 6 months.