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Continuous Glucose Monitoring to Reduce Hypoglycemia and Improve Safety in Patients With Hypoglycemia After Gastric Surgery

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03353415
Recruitment Status : Recruiting
First Posted : November 27, 2017
Last Update Posted : May 23, 2019
DexCom, Inc.
Information provided by (Responsible Party):
Joslin Diabetes Center

Brief Summary:
The purpose of this study is to see if the use of a continuous glucose monitor by people who experience low blood sugars (hypoglycemia) after gastric surgery can help reduce the number and severity of low blood sugar episodes.

Condition or disease Intervention/treatment Phase
Hypoglycemia, Reactive Hypoglycemia Device: Dexcom continuous glucose monitor Not Applicable

Detailed Description:
The continuous glucose monitor (CGM) that will be used in this study is already approved by the FDA for monitoring the glucose levels of people with diabetes. The investigators of this study are looking to see if this CGM will be able to benefit people who have had gastric surgery and experience low blood sugar episodes, which can be asymptomatic and lead to complications. This study will involve three to five visits, and involves wearing a sensor and regularly recording blood sugar values and any symptoms experienced as well as a record of treatments for symptoms. This study also involves the use of a fitness tracker, which will be worn for the duration of the 4 weeks of the study and returned at the end of the study. Participants will be able to keep the Dexcom CGM receiver and transmitter.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 28 participants
Intervention Model: Sequential Assignment
Intervention Model Description: The proposed study is designed to assess the efficacy of unmasked personal CGM to reduce the frequency of hypoglycemia after gastric surgery. Specifically, we will analyze glycemic patterns during 2 weeks of unmasked CGM wear, in comparison to the baseline 2 weeks of masked CGM wear. Please note that we have chosen to have a consistent masked monitoring first, as providing unmasked data to participants first could alter their dietary or other patterns and reduce ability of the study to independently assess efficacy of the CGM intervention.
Masking: None (Open Label)
Masking Description: The proposed study is designed to assess the efficacy of unmasked personal CGM to reduce the frequency of hypoglycemia after gastric surgery. Participants themselves will not be masked to study design. The only masking will be of the device itself during the first 2 weeks of the study.
Primary Purpose: Treatment
Official Title: Determining the Efficacy of Continuous Glucose Monitoring to Reduce Hypoglycemia and Improve Safety in Patients With Hypoglycemia After Gastric Surgery
Actual Study Start Date : February 7, 2019
Estimated Primary Completion Date : October 2019
Estimated Study Completion Date : October 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Hypoglycemia
Drug Information available for: Dextrose

Arm Intervention/treatment
Experimental: CGM Use
Each participant will wear the DexCom continuous glucose monitor for four weeks. During the first two weeks, participants will not be able to read the sensor glucose levels. In the second two weeks, participants will be able to read the sensor glucose levels. Frequency of hypoglycemia will be compared between the two phases of the study.
Device: Dexcom continuous glucose monitor
The CGM will monitor sensor glucose levels in all participants. During the first two weeks of the study, participants will be masked to the sensor glucose levels and will need to use other methods, such as a blood sample from a finger stick, to check their blood sugar. During the second two weeks, participants will be able to see the sensor glucose levels displayed from the CGM. Participants will be instructed to use this information to treat low glucose levels before symptoms or severely low glucose levels develop.

Primary Outcome Measures :
  1. Reduction in hypoglycemia [ Time Frame: 4 weeks ]
    The primary outcome will be hypoglycemia frequency and severity in masked vs. unmasked periods of CGM wear, as assessed by: (1) minutes per day <70 mg/dl, (2) minutes per day <55 mg/dl, (3) number of episodes requiring assistance, (4) episodes of severe hypoglycemia (<55 mg/dl), (5) episodes of moderate hypoglycemia (55-70 mg/dl), and (6) nocturnal hypoglycemia (11 PM to 6 AM).

Secondary Outcome Measures :
  1. Impact of lifestyle on glycemic patterns in post-bariatric hypoglycemia [ Time Frame: 4 weeks ]
    Activity measures, including total step number as well as duration of activity as defined by heart rate increment, will be analyzed to determine relationship to changes in sensor glucose levels. For all data, paired analysis will be used to compare responses per participant for masked vs. unmasked periods (2 weeks each).

  2. Reduction in glycemic variability [ Time Frame: 4 weeks ]
    CGM data will be analyzed to evaluate (1) number of episodes of hyperglycemia (>180 mg/dl) and (2) overall variability in glycemia.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Males or females diagnosed with ongoing post-bariatric or post-gastric surgery hypoglycemia with prior episodes of neuroglycopenia
  2. Age 18-65 years of age, inclusive, at screening
  3. Willingness to provide informed consent and follow all study procedures, including attending all scheduled visits.

Exclusion Criteria:

  1. Documented hypoglycemia occurring in the fasting state (> 12 hours fast);
  2. Chronic kidney disease stage 4 or 5 (including end-stage renal disease);
  3. Hepatic disease, including serum ALT or AST greater than or equal to 3 times the upper limit of normal; hepatic synthetic insufficiency as defined as serum albumin < 3.0 g/dL; or serum bilirubin >2.0;
  4. Congestive heart failure, NYHA class II, Ill or IV;
  5. History of myocardial infarction, unstable angina or revascularization within the past 6 months or 2 or more risk factors for coronary artery disease including diabetes, uncontrolled hypertension, uncontrolled hyperlipidemia, and active tobacco use.
  6. History of syncope (unrelated to hypoglycemia) or diagnosed cardiac arrhythmia
  7. Concurrent administration of 13-blocker therapy;
  8. History of a cerebrovascular accident;
  9. Seizure disorder (other than with suspect or documented hypoglycemia);
  10. Active treatment with any diabetes medications except for acarbose;
  11. Active treatment with octreotide or diazoxide;
  12. Active malignancy, except basal cell or squamous cell skin cancers;
  13. Personal or family history of pheochromocytoma or disorder with increased risk of pheochromocytoma (MEN 2, neurofibromatosis, or Von Hippel-Lindau disease);
  14. Known insulinoma;
  15. Major surgical operation within 30 days prior to screening;
  16. Hematocrit< 33%;
  17. Bleeding disorder, treatment with warfarin, or platelet count <50,000;
  18. Blood donation (1 pint of whole blood) within the past 2 months;
  19. Active alcohol abuse or substance abuse;
  20. Current administration of oral or parenteral corticosteroids;
  21. Pregnancy and/ or lactation: For women of childbearing potential: there is a requirement for a negative urine pregnancy test and for agreement to use contraception during the study and for at least 1 month after participating in the study. Acceptable contraception includes birth control pill/patch I vaginal ring, Depo-Provera, Norplant, an intrauterine device (IUD), the double barrier method (the woman uses a diaphragm and spermicide and the man uses a condom), or abstinence.
  22. Use of an investigational drug within 30 days prior to screening

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03353415

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Contact: Mary E Patti, MD (617) 309-2635
Contact: Lauren N Richardson, BS (617) 309-4463

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United States, Massachusetts
Joslin Diabetes Center Recruiting
Boston, Massachusetts, United States, 02215
Contact: Mary E Patti, MD    617-309-2635   
Contact: Lauren N Richardson, BS    (617) 309-4463   
Sponsors and Collaborators
Joslin Diabetes Center
DexCom, Inc.
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Principal Investigator: Mary E Patti, MD Joslin Diabetes Center

Additional Information:
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Responsible Party: Joslin Diabetes Center Identifier: NCT03353415    
Other Study ID Numbers: 2017-27
First Posted: November 27, 2017    Key Record Dates
Last Update Posted: May 23, 2019
Last Verified: May 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Keywords provided by Joslin Diabetes Center:
Post-bariatric Hypoglycemia;
Additional relevant MeSH terms:
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Glucose Metabolism Disorders
Metabolic Diseases