Clinical trial NCT03353415: Continuous Glucose Monitoring to Reduce Hypoglycemia and Improve Safety After Gastric Surgery
Official title: Determining the Efficacy of Continuous Glucose Monitoring to Reduce Hypoglycemia and Improve Safety in Patients With Hypoglycemia After Gastric Surgery
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypoglycemia, Reactive
Hypoglycemia
Keywords: Post-bariatric Hypoglycemia;
Lead sponsor: Joslin Diabetes Center
Sponsor class: OTHER
Collaborators: name: DexCom, Inc.
First posted: 2017-11-27
Enrollment: 26
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: SEQUENTIAL
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 a phase of baseline masked CGM wear (2 weeks for the Dexcom G4 or 10 days for the Dexcom G6), in comparison to a sequential, second phase of unmasked CGM wear (2 weeks for the Dexcom G4 or 10 days for the Dexcom G6). 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.
Primary purpose: TREATMENT

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).

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.

Primary outcomes:
measure: Percentage of Time Sensor Glucose <70 mg/dL in the Masked Versus the Unmasked Phase.
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Percentage of Time Sensor Glucose <60mg/dL in the Masked Versus the Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Percentage of Time Sensor Glucose <54 mg/dL in the Masked Versus the Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
Secondary outcomes:
measure: Median Sensor Glucose Level During Masked Versus Unmasked Phases of Wear
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Mean Sensor Glucose Level During Masked Versus Unmasked Phases of Wear
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Peak Sensor Glucose Level During Masked Versus Unmasked Period of CGM Wear
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Sensor Glucose Level Range (Highest Sensor Glucose Minus Lowest Sensor Glucose mg/dL) During Masked Versus Unmasked Period of CGM Wear
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Nadir Sensor Glucose Level During Masked Versus Unmasked Period of CGM Wear
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Percent of Time Sensor Glucose 70-180 mg/dL During Period of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Percentage of Time Sensor Glucose Level >180 mg/dL During Period of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Percentage of Time Sensor Glucose Level >250 mg/dL During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Glycemic Variability as Measured by the Standard Deviation of Sensor Glucose Level Data During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Mean Coefficient of Variation of Sensor Glucose Data During Period of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Mean Amplitude of Glycemic Excursion (MAGE) of Sensor Glucose Levels During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: 24 Hour Continuous Overall Net Glycemic Action (CONGA) for Sensor Glucose Data During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: 1 Hour Continuous Overall Net Glycemic Action (CONGA) for Sensor Glucose Data During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: 2 Hours, Continuous Overall Net Glycemic Action (CONGA) for Sensor Glucose Data During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: 4 Hours, Continuous Overall Net Glycemic Action (CONGA) for Sensor Glucose Data During Periods of CGM Wear, Masked Versus Unmasked Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Total Number of Hypoglycemic Events During the Masked Versus the Unmasked Phases of CGM Wear, as Defined by a Sensor Glucose <70 mg/dL, for at Least 15 Minutes
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Total Number of Hypoglycemic Events Defined by a Sensor Glucose <60 mg/dL, for at Lease 15 Minutes, During the Masked Versus Unmasked CGM Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
measure: Total Number of Hypoglycemic Events Defined by a Sensor Glucose <54 mg/dL, for at Least 15 Minutes, During the Masked Versus Unmasked CGM Phase
timeFrame: 28 days for those participants wearing Dexcom G4, and 20 days for participants wearing Dexcom G6.
Other outcomes:
Locations:
city: Boston
country: United States
facility: Joslin Diabetes Center
state: Massachusetts
Study officials:
affiliation: Joslin Diabetes Center
name: Mary Elizabeth Patti, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.