Clinical trial NCT00831389: Effect of Closed Loop Glucose Control on Exercise-Associated Hypoglycemia
Official title: Effect of Closed Loop Glucose Control on Exercise-Associated Hypoglycemia
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Type 1 Diabetes Mellitus
Lead sponsor: Medtronic Diabetes
Sponsor class: INDUSTRY
Collaborators: name: Juvenile Diabetes Research Foundation
First posted: 2009-01-28
Enrollment: 13
Sex: ALL
Minimum age (years): 12
Maximum age (years): 30
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: OTHER

Brief summary: The purpose of the study is to compare the glycemic control during and following aerobic exercise using either an open or closed-loop insulin delivery system.

Detailed description: This is an open-label, single-center, randomized crossover study evaluating the performance of a closed-loop insulin delivery system using a subcutaneous glucose sensor and an external insulin pump and comparing it to an open-loop delivery system during aerobic exercise. Subject participation will be for a maximum of 16 weeks including an outpatient study (up to 6 days) and two inpatient studies (one closed-loop; the other open-loop). The closed- and open-loop visit consists of approximately 67 hours over 4 days and 3 nights.

Eligibility criteria: Inclusion Criteria:

* Male and female subjects between 12-30 years of age.
* Subjects must weigh at least 50 kg to accommodate phlebotomy.
* Previously diagnosed Type 1 Diabetes Mellitus
* Diabetes duration at least 1 year.
* Currently treating their diabetes with an insulin pump.
* A1C of ≤ 9.0 % at time of enrollment.
* Willing to have an intravenous (IV) line inserted for frequent blood sampling and infusion of glucose if needed.
* Willing to wear two (2) subcutaneous glucose sensors and two (2) transmitters simultaneously during closed-loop portion of the study.
* Be in good general health without other acute or chronic illnesses except treated hypothyroidism or celiac disease and asthma not requiring glucocorticoid use.
* Able to tolerate a 75-minute exercise period of moderate intensity.
* Speak and understand English.
* Subject and parent (if minor) must be able to comprehend and sign the informed consent form and other study documents.

Exclusion Criteria:

* Pregnancy (urine pregnancy test) or lactation, if female.
* Subject has any major concomitant disease or any physical or psychological disorder within the last five years, which might be considered life threatening, or which might confound the collection or interpretation of the study data.
* Subject has a cardiac pacemaker or similar device that may be sensitive to radio frequency telemetry.
* Subject using any of the following medications:

  * glucocorticoids
  * cyclosporine
  * L-asparaginase
  * niacin
  * protease inhibitors
  * anti-psychotics
  * GnRH agonists
  * beta-blockers
  * calcium channel blockers
  * immunosuppressants
  * over-the-counter medications that may effect glucose metabolism.
* Subject has any of the following conditions

  * insulin allergy
  * severe insulin resistance
  * exercise-induced asthma
  * musculoskeletal problems that may impact ability to complete exercise protocol
  * substance abuse
  * skin ulcers or poor wound healing
  * bleeding disorders
  * chronic infections
  * eating disorders
  * give a history of or are predisposed to major stress
  * any other major organ system disease.
* Subject has experienced two (2) or more severe hypoglycemic events -seizures/coma requiring assistance in the past six (6) months.
* Subject has any other condition that in the investigator's opinion warrants exclusion from the study or precludes him/her from completing the protocol.
* Subjects using dietary supplements within 14 days of study enrollment
* Subject is currently enrolled in another study.

Primary outcomes:
measure: Plasma Glucose (PG) Response to Exercise
timeFrame: Begins at start of exercise, at or after 15:00 on the in-patient visit day randomly assigned each subject for exercise; ends at start of the subsequent meal. Median period: 121 minutes (min), interquartile range (IQR): 15 min, range: 93 to 133 min.
measure: Incidence of Hypoglycemia Immediately Following Exercise
timeFrame: Begins at end of exercise, at or after 16:15 on the in-patient visit day randomly assigned each subject for exercise; ends at 22:00 of same day. Median period: 333 minutes (min), interquartile range (IQR): 28 min, range: 262 to 344 min.
measure: Incidence of Nocturnal Hypoglycemia Following Exercise
timeFrame: Begins at 22:00 on the in-patient visit day randomly assigned each subject for exercise; ends at 6:00 of the subsequent day. Period was 480 minutes (min) for all subjects, both study phases.
Secondary outcomes:
measure: Peak Post-prandial Plasma Glucose (PG)
timeFrame: Union of 6 meal periods (3 per day on study days 2 & 3). A meal period runs from meal start to start of next meal, or 22:00 for 3rd meal of the day. Union of 6 periods median: 1666 minutes (min), interquartile range (IQR): 15 min, range: 1638 to 1680 min.
measure: Nadir Plasma Glucose (PG) Immediately Following Exercise
timeFrame: Begins at start of exercise, at or after 15:00 on the in-patient visit day randomly assigned each subject for exercise; ends at start of the subsequent meal. Median period: 121 minutes (min), interquartile range (IQR): 15 min, range: 93 to 133 min.
measure: Overnight Nadir Plasma Glucose (PG)
timeFrame: Union of the two 8-hour overnight periods beginning at 22:00 on in-patient visit days 2 & 3, ending at 6:00 on the subsequent day. The union of the two periods was 960 minutes (min) for all subjects, both study phases.
measure: Percentage of Time Plasma Glucose (PG) is Within the Euglycemic Range.
timeFrame: Begins at 6:00 of in-patient visit day 2 and ends at 6:00 of day 4; 48 hours total.
measure: Percentage of Time Plasma Glucose (PG) is Above the Euglycemic Range.
timeFrame: Begins at 6:00 of in-patient visit day 2 and ends at 6:00 of day 4; 48 hours total.
measure: Percentage of Time Plasma Glucose (PG) is Below the Euglycemic Range.
timeFrame: Begins at 6:00 of in-patient visit day 2 and ends at 6:00 of day 4; 48 hours total.
Other outcomes:
Locations:
city: New Haven
country: United States
facility: Yale Pediatrics Diabetes Research
state: Connecticut
Study officials:
affiliation: Yale University
name: Stuart Weinzimer, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Sherr JL, Cengiz E, Palerm CC, Clark B, Kurtz N, Roy A, Carria L, Cantwell M, Tamborlane WV, Weinzimer SA. Reduced hypoglycemia and increased time in target using closed-loop insulin delivery during nights with or without antecedent afternoon exercise in type 1 diabetes. Diabetes Care. 2013 Oct;36(10):2909-14. doi: 10.2337/dc13-0010. Epub 2013 Jun 11.