In-ear blood flow monitoring for people with low blood sugar after weight-loss surgery

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

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.

Why it matters

Who can join: the full rules

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 it's running

• 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

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.