In-ear blood flow monitoring for people with low blood sugar after weight-loss surgery
External Carotid Blood Flow Dynamics in Individuals With Post-Bariatric Hypoglycemia (PBH): Pilot Study
This pilot will try a small in-ear wearable that measures head blood flow in adults with post-bariatric hypoglycemia and compare results to surgical and non-surgical control groups.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 5 (estimated) |
| Ages | 18 Years to 70 Years |
| Sex | All |
| Sponsor | Joslin Diabetes Center Academic / other |
| Locations | 1 site (Boston, Massachusetts) |
| Trial ID | NCT07082478 on ClinicalTrials.gov |
What this trial studies
This is a pilot, first-phase observational effort using a novel in-ear wearable (Lumia Health) to record blood flow changes to the head in adults with post-bariatric hypoglycemia and several comparison groups. Participants complete a screening visit at Joslin Diabetes Center with medical history review, ear exam, vital signs, and symptom questionnaires, then use the device and keep daily food, activity, and symptom diaries. The primary aim of this phase is to test comfort and feasibility of the device and study procedures before deciding whether to advance to a second phase. Data collected will be used to determine if the device reliably captures blood-flow changes during hypoglycemia and if study methods are practical for a larger study.
Who should consider this trial
Good fit: Adults aged 18–70 with post-bariatric hypoglycemia (or the specified comparison groups), able to consent, complete diaries/questionnaires, attend visits at Joslin in Boston, and use a personal iPhone running iOS 16 or later with home Wi‑Fi are ideal candidates.
Not a fit: People with recent coronary disease, recent myocardial infarction/revascularization, syncope unrelated to hypoglycemia, diagnosed cardiac arrhythmia, or those without a compatible iPhone/Wi‑Fi are excluded and unlikely to benefit from participation.
Why it matters
Potential benefit: If successful, the device could offer a noninvasive way to detect or monitor cerebral blood-flow changes during low blood sugar, which may improve recognition and management of post-bariatric hypoglycemia.
How similar studies have performed: Noninvasive cerebral blood-flow monitoring has been used in other contexts, but in-ear wearable devices like Lumia Health are a novel approach and remain largely untested in post-bariatric hypoglycemia.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * 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. Exclusion Criteria: * 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 this trial is running
Boston, Massachusetts
- Joslin Diabetes Center — Boston, Massachusetts, United States (Recruiting)
Study contacts
- Principal investigator: Mary E Patti, M.D. — Joslin Diabetes Center
- Study coordinator: Gabriela Londono, B.S.
- Email: glondono@joslin.harvard.edu
- Phone: 6173091940
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.