External Carotid Blood Flow in Individuals With Post-Bariatric Hypoglycemia

Recruiting now

Conditions studied: Hypoglycemia, Cerebral Blood Flow

In brief

This is a pilot study (small-scale study) that aims to understand more about how blood flow changes in people who have low blood sugar after bariatric surgery (post-bariatric hypoglycemia) compared to those who have had surgery without hypoglycemia, those who have hypoglycemia without surgery, or those who do not experience low blood sugar. This study has two phases. This is the first phase, and the purpose is to test comfort and feasibility of a novel in-ear wearable device (Lumia Health) that measures blood flow changes to the head. Information from the study will help the investigators determine if the device is suitable to be used in the second phase of the study.

Key facts

Study ID

NCT07082478

Run by

Joslin Diabetes Center

People needed

5

Starts

2025-07-28

Expected to finish

2026-09-15

Last updated by the study team

2025-11-28

Who can join

Age: 18 and older, up to 70. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• Age 18-70 years of age, inclusive at screening.
• Individuals able to provide informed consent and follow all study procedures, including complete daily food, activity, and symptom diaries, and willingness to provide access to medical record review.
• For healthy control group: individuals without a history of upper gastrointestinal surgery and without reported symptoms of hypoglycemia.
• Individuals with access to personal iPhone running operating system 16 (iOS) or later versions (not feasible for Android platform users) and a password-protected home Wi-Fi network.

You may not qualify if…

• History of coronary artery disease or presence of 2 or more risk factors including diabetes, uncontrolled hypertension, uncontrolled hyperlipidemia, and active tobacco use.
• History of myocardial infarction, unstable angina or revascularization within the past 6 months.
• History of syncope (unrelated to hypoglycemia) or diagnosed cardiac arrhythmia.
• Documented hypoglycemia occurring in the fasting state (> 12 hours fast).
• Concurrent administration of β-blocker therapy.
• Vigorous physical activity within 24 hours prior to assessment.
• Seizure disorder (other than with suspect or documented hypoglycemia).
• Hematocrit < 33% (women) or <36% (men) within the past 6 months.
• History of insulinoma.
• Use of central nervous system-active medications, including: antidepressants, anxiolytics, antipsychotics, stimulants, antiepileptics, sedatives and opioids.
• History of severe neurologic vascular disease (e.g. cerebrovascular disease/stroke).
• History of previous diseases associated with dysautonomia (e.g. multiple system atrophy, multiple sclerosis, Parkinson's disease).
• Impaired hepatic function (aspartate amino transaminase and/or alanine amino transaminase >2x upper limit of normal range), as determined within the past 6 months.
• Impaired renal function (serum creatinine >1.5 mg/dL), as determined within the past 6 months.
• Serious psychiatric or substance abuse disorders (e.g. alcohol, opioid, cocaine use disorder), as judged by the study investigator.
• Non-consent or inability to comply with study procedures.
• Current pregnancy and/ or lactation.
• Vulnerable individuals (e.g., fetuses, children, prisoners) and those judged by the investigator to be unsuitable for the study.
• Individuals wearing earrings or other jewelry in the left ear who are unable or unwilling to remove them for the duration of the study.
• Unwillingness to wear study masked CGM for duration of study

Where it is running

• Joslin Diabetes Center — Boston, Massachusetts, United States (enrolling)

Full record on ClinicalTrials.gov

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