Adjusting Insulin Delivery to Activity
Condition: Diabetes; Nocturnal Hypoglycemia
MeSH terms: Hypoglycemia
Study type: Interventional

Summary: 
      Increased daytime activity in children and adolescents with type I diabetes is known to be
      associated with overnight hypoglycemia. We therefore wish to perform a prospective clinical
      study to assess the feasibility of using activity monitor data to adjust insulin pump basal
      rates and see whether we can help prevent overnight hypoglycemia or decrease related
      interventions following high activity days. We plan to carry this out by enrolling 20
      subjects (10 subjects 1 to <7 years old and 10 subjects 7 to 17 years old) with type 1
      diabetes managed on insulin pump therapy and having them wear activity monitors and CGMs for
      up to 3 months. After an initial two-week period to establish activity baselines, we will
      recommend nighttime basal insulin rate adjustments based on activity monitor, CGM and insulin
      pump data.
    

Detailed description: 
      This study is a pilot trial investigating the feasibility of using activity monitoring data
      to adjust insulin pump therapy and prevent hypoglycemia. The study will enroll 20 patients
      with type 1 diabetes mellitus on insulin pump therapy, 10 from each of two age groups:
      younger children aged 1 year to <7 years of age, and older children aged 7-17 years of age.
      Subjects will be provided with continuous glucose monitors (DexCom G4) and activity monitors.
      Study duration will be up to 3 months. During the course of the study patients will continue
      to receive routine care by their primary endocrinologist and diabetes nurse educator (DNE).
      Insulin dose adjustments unrelated to activity monitor data will continue to be at the
      discretion of the patient's primary diabetes team.

      Activity level (steps and calories burned) will be uploaded over the web in a secure fashion
      to our central firewall-protected database on a daily basis while CGM glucose values and
      insulin pump data will be collected once a week. The initial 2 weeks of a subject's
      enrollment in the study will be used to establish his or her baseline activity level and no
      changes to the insulin regimen will be made based on the activity monitor data. During weeks
      3 to 12, activity data will be reviewed daily and an alternate basal insulin rate will be
      recommended on days considered to be increased activity days. We will use an adaptive
      algorithm to help guide suggested insulin basal rate changes. All recommendations will be
      reviewed and approved by a physician prior to implementation. The alternate rate will be
      derived using the subject's usual care pump settings as an initial starting point from which
      to make incremental changes in the 3 hour interval leading up to the hypoglycemic event.
      Target will be the overnight nadir obtained with usual care settings. Residual error
      (CGM-target) will be used to assess the validity of using the 3 hour window prior to the
      event to effect lower basal.
    

Intervention name(s): Dexcom G4 Platinum CGM; Activity monitor
Intervention type(s): Device; Device
Intervention description(s): Blood glucose levels will be monitored using continuous glucose monitors (CGMs). Participants will be asked to verify CGM low blood sugars using their home glucometer. Insulin dose adjustments will be made if there is concern that nocturnal hypoglycemia is occurring in relation to high daytime activity.; Participants will be asked to wear an activity monitor so that we may assess their daily activity level. Insulin dose adjustments will be made if there is concern that nocturnal hypoglycemia is occurring in relation to high daytime activity.
Other intervention name(s): Continuous glucose monitor and activity monitor
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: insulin pump; continuous glucose monitor; activity monitor