Recruiting

Lumia Health

Sponsor:

Joslin Diabetes Center

Code:

NCT07082478

Conditions

Hypoglycemia

Cerebral Blood Flow

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Accepted

Interventions

in-ear device measuring blood flow

Study Details

Brief summary:

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.

Conditions

Hypoglycemia

Cerebral Blood Flow

Study ID

NCT07082478

Start date

Jul 28, 2025

Status verified date

Nov, 2025

Completion date

Sep 15, 2026

Anticipated

Primary completion date

Sep 15, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Accepted

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

Study Design

Enrollment

5 participants

Anticipated

Interventions and Outcome Measures

Arms

healthy individuals

individuals with no history of hypoglycemia or upper gastrointestinal surgery

Interventions

in-ear device measuring blood flow

A small in-ear wearable device will be placed to monitor the blood flow to the head. The investigators will make sure it fits comfortably and show the participant how to use it properly.

Dexcom G6 Pro: This continuous glucose monitor (CGM) will be placed under the skin of the abdomen to monitor sensor sugar levels.

These sensors will be placed during visit one and will be worn together for 10 days. A followup visit (visit 2) will occur remotely at 4-6 days later. A final visit will occur after 10 days when the device will be removed.

Primary outcome measure

  • Rate of study completion [ Time Frame: up to 10 days ]
  • Number of days with viable data (complete recordings) [ Time Frame: up to 10 days ]
  • Participant-reported outcome scores [ Time Frame: up to 10 days ]
  • Correlation between external cerebral blood flow (eCBF) (arbitrary units) and corresponding sensor glucose values (mg/dL) [ Time Frame: up to 10 days ]
  • Correlation between rate of change in eCBF (arbitrary units) and rate of change in sensor glucose (mg/dL) [ Time Frame: up to 10 days ]

Central Contacts and Locations

Central contacts

Gabriela Londono, B.S.

6173091940glondono@joslin.harvard.edu

Lily Swaine-Moore, B.S.

6173094468lswainem@joslin.harvard.edu

Locations

Joslin Diabetes Center

Recruiting

Boston, Massachusetts, United States, 02215

Contacts

Yael Sarig, B.A.

617-309-1940sarigy@joslin.harvard.edu

Principal Investigator:

Mary E Patti, M.D.

More Information

Sponsor

Joslin Diabetes Center

Last update posted

Nov 28, 2025

Last verified

Nov, 2025

Keywords

  • hypoglycemia
  • postprandial hypoglycemia
  • bariatric surgery
  • autonomic dysfunction
  • cerebral blood flow

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Joslin Diabetes Center on 2025-11-28.