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

NCT ID: NCT03353415

Last Updated: 2023-08-28

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 26 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-02-07
• Study Completion Date: 2023-04-12

Brief Summary

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

Detailed Description

The CGM devices used in this study are approved by the Food and Drug Administration (FDA) for monitoring the glucose levels of people with diabetes. The investigators of this study are looking to see if these CGM devices are able to benefit people who have had gastric surgery and experience low blood sugar episodes, which can be asymptomatic and lead to complications, impairing safety. This study involves wearing a CGM sensor/transmitter during first a masked phase (unable to see CGM sensor glucose levels), followed by an unmasked phase (able to see and respond to sensor glucose levels and alarms). Participants are asked to regularly record fingerstick (capillary) blood sugar values and any symptoms experienced, as well as a record of treatments for symptoms and glucose levels.

Participants attend three to five study visits: 5 visits for participants who wore the Dexcom G4, and 3 visits for participants who wore the Dexcom G6. The Dexcom G4 became unavailable during the course of the study when the G6 was introduced. (The Dexcom G4 had a 7 day wear period versus a 10 day wear period for the G6. As the G6 has a longer wear period, the frequency of the study visits was able to be decreased).

This study also involves the use of a fitness tracker, which will be worn for the duration of the study and returned at the end of the study.

Participants wearing the Dexcom G4 device were able to keep the Dexcom G4 CGM receiver and transmitter (this was not possible with the Dexcom G6 system).

Conditions

Hypoglycemia, Reactive; Hypoglycemia

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Masked CGM Wear (Phase 1)

Each participant will wear the Dexcom CGM for two sequential phases. During the first phase, participants will not be able to read the sensor glucose levels (masked).

Group Type: OTHER

Dexcom CGM masked

Intervention Type: DEVICE

The CGM will monitor sensor glucose levels in all participants. (Initially the Dexcom G4 was worn by participants (n=13); however, when the G4 became unavailable, the G6 was worn by the subsequent participants (n=10)).

The duration of the Dexcom G4 sensor was 7 days (2 sensors placed during each phase of participation) versus the Dexcom G6 whose sensor duration is 10 days (1 sensor placed during each phase of participation).

Unmasked CGM Wear (Phase 2)

In the second phase, participants will be able to read the sensor glucose levels (unmasked). Frequency of hypoglycemia will be compared between the two phases of the study.

Group Type: EXPERIMENTAL

Dexcom CGM unmasked

Intervention Type: DEVICE

During the second phase (2 weeks for the Dexcom G4 and 10 days for the Dexcom G6), participants are 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.

The duration of the Dexcom G4 sensor was 7 days (2 sensors placed during each phase of participation) versus the Dexcom G6 whose sensor duration is 10 days (1 sensor placed during each phase of participation).

Interventions

Dexcom CGM masked

The CGM will monitor sensor glucose levels in all participants. (Initially the Dexcom G4 was worn by participants (n=13); however, when the G4 became unavailable, the G6 was worn by the subsequent participants (n=10)).

The duration of the Dexcom G4 sensor was 7 days (2 sensors placed during each phase of participation) versus the Dexcom G6 whose sensor duration is 10 days (1 sensor placed during each phase of participation).

Intervention Type: DEVICE

Dexcom CGM unmasked

During the second phase (2 weeks for the Dexcom G4 and 10 days for the Dexcom G6), participants are 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.

The duration of the Dexcom G4 sensor was 7 days (2 sensors placed during each phase of participation) versus the Dexcom G6 whose sensor duration is 10 days (1 sensor placed during each phase of participation).

Intervention Type: DEVICE

Eligibility Criteria

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 alanine transaminase (ALT) or aspartate aminotransferase (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, New York Heart Association (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 beta-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 (multiple endocrine neoplasia (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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

DexCom, Inc.

INDUSTRY

Sponsor Role: collaborator

Joslin Diabetes Center

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Mary Elizabeth Patti, MD

Role: PRINCIPAL_INVESTIGATOR

Joslin Diabetes Center

Locations

Joslin Diabetes Center

Boston, Massachusetts, United States

Countries

United States

References

Patti ME, Goldfine AB. The rollercoaster of post-bariatric hypoglycaemia. Lancet Diabetes Endocrinol. 2016 Feb;4(2):94-6. doi: 10.1016/S2213-8587(15)00460-X. Epub 2015 Dec 15. No abstract available.

Reference Type: BACKGROUND

PMID: 26701701 (View on PubMed)

Cummings C, Jiang A, Sheehan A, Ferraz-Bannitz R, Puleio A, Simonson DC, Dreyfuss JM, Patti ME. Continuous glucose monitoring in patients with post-bariatric hypoglycaemia reduces hypoglycaemia and glycaemic variability. Diabetes Obes Metab. 2023 Aug;25(8):2191-2202. doi: 10.1111/dom.15096. Epub 2023 May 3.

Reference Type: RESULT

PMID: 37046360 (View on PubMed)

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

2017-27

Identifier Type: -

Identifier Source: org_study_id