Dexmedetomidine Trial for Effects on Rhythms, Sleep Architecture, and Biomarker Dynamics in Older Adults (DEXTER)

Dexmedetomidine Trial for Effects on Rhythms, Sleep Architecture, and Biomarker Dynamics - A Pilot Study (DEXTER)

The DEXTER study is a cross-over, double-blind, placebo-controlled pilot research study led by Dr. Peng Li. The goal of this project is to evaluate the safety, feasibility, and biological effects of a single dose of sublingual (under-the-tongue) dexmedetomidine (SL Dex) in older adults. Specifically, researchers want to see how this medication affects sleep patterns, internal 24-hour circadian rhythms, and the daily cycles of certain neurological proteins (specifically plasma p-tau217) associated with brain aging.

Study Overview

• Status: Not yet recruiting
• Conditions: Sleep; Circadian Rhythm
• Intervention / Treatment: Drug: Dexmedetomidine sublingual film; Drug: Placebo Sublingual Film

Detailed Description

Circadian rhythms are fundamental regulators of human physiology, coordinating sleep-wake timing, neural activity, metabolic processes, and hormonal signaling across the 24-hour day. These endogenous rhythms are coordinated by the suprachiasmatic nucleus (SCN), the central circadian pacemaker in the hypothalamus that integrates environmental cues such as light to synchronize peripheral and central biological processes. In older adults, circadian rhythms often degrade, exhibiting reduced robustness and impaired alignment with behavioral cycles. Such alterations are closely linked to disrupted sleep architecture, particularly sleep fragmentation and loss of restorative non-rapid eye movement (NREM) sleep. Crucially, sleep and circadian dysfunction is increasingly recognized as a critical modulator of neurodegenerative biomarker dynamics. Experimental evidence suggests that fragmented sleep and reduced slow-wave sleep directly alter the production, release, and clearance of neurotoxic proteins, leading to elevated tau levels. These observations highlight a potential mechanistic pathway linking sleep-circadian dysfunction to neurodegeneration and underscore the need to understand how interventions that stabilize these systems influence the temporal profile of tau-related biomarkers. Dexmedetomidine, a highly selective alpha2-adrenergic receptor agonist, represents a unique pharmacologic probe for investigating the links between sleep architecture, circadian physiology, and tau biomarker dynamics. Unlike traditional sedatives, dexmedetomidine engages endogenous sleep-promoting pathways and produces a NREM-like state characterized by electrophysiologic features resembling natural sleep. Beyond its sleep-modulating properties, emerging preclinical evidence suggests that dexmedetomidine exerts potent chronobiotic effects (i.e., the ability to stabilize or entrain circadian rhythms). For instance, preclinical models indicate it activates vasoactive intestinal peptide (VIP) neurons within the SCN and modulates circadian entrainment processes. Clinical studies of thoracic surgery patients further suggest that dexmedetomidine may preserve endogenous circadian signaling, such as melatonin secretion, during the early postoperative period. The recent development of sublingual dexmedetomidine (SL Dex) provides a transformative, noninvasive formulation that enables controlled administration outside of intensive care settings, distinguishing it from traditional intravenous (IV) dexmedetomidine, which is typically limited to monitored environments. Preliminary studies have suggested that SL Dex produces measurable changes in sleep architecture, including increased slow-wave activity, shortened sleep latency, and prolonged REM sleep latency. However, the extent to which SL Dex influences circadian regulation, sleep architecture, and the temporal profile of tau biomarkers across the 24-hour sleep-wake cycle in humans has not been systematically characterized. Addressing this gap requires a rigorously controlled experimental approach capable of isolating the physiologic effects of SL Dex from environmental and behavioral confounders. Prior clinical studies have largely occurred in perioperative or other medically complex settings in which surgery, pain, inflammation, environmental disruption, concomitant medications, and irregular behaviors may confound interpretation of sleep and circadian outcomes. An in-laboratory protocol that standardizes light exposure, posture, feeding, activity, and sampling timing provides a necessary platform to isolate these effects. Determining whether SL Dex produces not only sleep-like sedation, but also measurable sleep/circadian effects and tau dynamics would provide important insights into the relationship between pharmacologic modulation of sleep-circadian biology and inform future translational studies in aging and neurobiology.

Specific Aims and Objectives: This study aims to evaluate the feasibility, safety, and physiologic effects of sublingual dexmedetomidine (SL Dex) on sleep architecture, circadian physiology, and tau biomarker dynamics in older adults under controlled laboratory conditions. SL Dex represents a novel, noninvasive approach to modulating sleep and circadian biology and provides a unique opportunity to examine downstream effects on neurodegenerative biomarkers. Specifically, this study aims to:

1. Assess the feasibility and safety of administering SL Dex within a controlled in-laboratory sleep and circadian protocol with ambulatory follow-up.
2. Quantify the acute effects of SL Dex on sleep architecture, circadian physiology, and tau dynamics under controlled experimental conditions.
3. Characterize the duration and trajectory of SL Dex-associated effects on sleep and circadian physiology during ambulatory follow-up.

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Chenlu Gao, PhD; Phone Number: 617-643-9515; Email: cgao6@mgh.harvard.edu

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02115
      • Brigham and Women's Hospital
      • Contact: Peng Li, PhD; Phone Number: 617-643-9514; Email: pli9@mgh.harvard.edu
    • Boston, Massachusetts, United States, 02129
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 65 years or older
• Able to provide informed consent
• Willing and able to comply with all study procedures, including in-laboratory and ambulatory monitoring
• Able to provide informed consent using an IRB-approved translated consent document (when available) and complete study procedures with translated materials and/or qualified interpreter services, if needed- Stable residence and sleep schedule sufficient to complete study monitoring periods
• Able to safely discontinue or adjust medications that may interfere with study procedures or outcomes, as determined by the study investigator

Exclusion Criteria:

• Clinically significant sleep disorders including narcolepsy, severe obstructive sleep apnea, REM sleep behavior disorder, or periodic limb movement disorder
• Clinically significant cardiovascular disease including bradyarrhythmia, conduction abnormalities, heart failure, cardiomyopathy, ischemic heart disease, or conditions increasing risk with dexmedetomidine
• Known QT prolongation, clinically significant arrhythmias, symptomatic bradycardia, hypokalemia, hypomagnesemia, or concurrent use of QT-prolonging medications
• Contraindication or allergy to dexmedetomidine or study medications
• Severe hepatic impairment
• Neurologic, psychiatric, or substance use disorders that may interfere with participation or data interpretation
• Use of medications significantly affecting sleep, circadian rhythms, or cardiovascular function
• Gastrointestinal conditions increasing risk of capsule retention or bowel obstruction
• Swallowing disorders or aspiration risk
• Presence of implantable electronic medical devices
• Use of anticoagulant or antiplatelet medications increasing bleeding risk
• Pregnancy or breastfeeding
• Shift work or frequent travel across more than two time zones
• Participation in another interventional study that may interfere with study participation or interpretation of results
• Anticipated need for MRI during the period in which the ingestible telemetry capsule may remain in the body
• Inability to tolerate study procedures (blood draws, PSG, wearable devices, ingestible capsule)
• Unable to provide informed consent even with translated materials/interpreter support
• Previous participation in this trial
• Concurrent interventional studies that may interfere with participation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sublingual Dexmedetomidine First; Participants receive a single 120 mcg dose of sublingual dexmedetomidine (IGALMI®) during the first in-laboratory study period and matched placebo during the second study period after a washout interval of at least 3 weeks. The study evaluates effects on sleep architecture, circadian physiology, and plasma tau biomarker dynamics under controlled laboratory conditions.	Drug: Dexmedetomidine sublingual film; Participants receive a single 120 mcg dose of sublingual dexmedetomidine (IGALMI®) administered approximately 15-20 minutes before the scheduled sleep opportunity during the in-laboratory protocol.; Drug: Placebo Sublingual Film; Participants receive a matched placebo sublingual film identical in appearance, packaging, and administration method to the active dexmedetomidine formulation but containing no active medication.
Placebo Comparator: Placebo First; Participants receive matched placebo during the first in-laboratory study period and a single 120 mcg dose of sublingual dexmedetomidine (IGALMI®) during the second study period after a washout interval of at least 3 weeks. The study evaluates effects on sleep architecture, circadian physiology, and plasma tau biomarker dynamics under controlled laboratory conditions.	Drug: Dexmedetomidine sublingual film; Participants receive a single 120 mcg dose of sublingual dexmedetomidine (IGALMI®) administered approximately 15-20 minutes before the scheduled sleep opportunity during the in-laboratory protocol.; Drug: Placebo Sublingual Film; Participants receive a matched placebo sublingual film identical in appearance, packaging, and administration method to the active dexmedetomidine formulation but containing no active medication.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Adverse Events	Number of participants experiencing one or more adverse events during the study, including hypotension, bradycardia, and excessive sedation.	From first study intervention through completion of the 10-day ambulatory follow-up following the second study period
Proportion of Participants Completing the Study	Proportion of enrolled participants who complete both study periods, including the in-laboratory protocols and post-laboratory ambulatory follow-up.	Through completion of the 10-day ambulatory follow-up following the second study period
Proportion of Consented Participants Who Are Randomized	Proportion of participants who provide informed consent and are subsequently randomized to a study intervention sequence, calculated as the number of randomized participants divided by the total number of participants who provide informed consent.	At randomization, prior to the first study intervention
Proportion of Participants Completing the In-Laboratory Protocol	Proportion of enrolled participants who complete the 3-night in-laboratory protocol during both study periods.	Through completion of the second 3-night in-laboratory study period
Proportion of Participants Completing Ambulatory Follow-Up	Proportion of enrolled participants who complete the 10-day post-laboratory ambulatory monitoring period during both study periods.	Through completion of the 10-day ambulatory follow-up following the second study period
Proportion of Required Actigraphy Monitoring Completed	Proportion of required actigraphy monitoring completed by participants across the pre-laboratory and post-laboratory ambulatory monitoring periods.	Through completion of the 10-day ambulatory follow-up following the second study period
Proportion of Required Polysomnography Assessments Completed	Proportion of required in-laboratory polysomnography assessments completed by participants.	Through completion of the second 3-night in-laboratory study period
Proportion of Required Wearable EEG Assessments Completed	Proportion of required ambulatory wearable EEG assessments completed by participants.	Through completion of the 10-day ambulatory follow-up following the second study period
Proportion of Required Sleep Diaries Completed	Proportion of required sleep diary assessments completed by participants during ambulatory monitoring.	Through completion of the 10-day ambulatory follow-up following the second study period
Number of Participants Withdrawing Due to Adverse Effects	Number of participants who withdraw from the study or discontinue study procedures because of adverse effects.	From first study intervention through completion of the 10-day ambulatory follow-up following the second study period
Heart Rate Before and After Study Drug Administration	Heart rate measured before and after administration of sublingual dexmedetomidine or placebo to assess hemodynamic safety and tolerability. Heart rate will be reported in beats per minute.	Pre-dose and post-dose on Day 2 of each 3-day in-laboratory study period
Systolic Blood Pressure Before and After Study Drug Administration	Systolic blood pressure measured before and after administration of sublingual dexmedetomidine or placebo to assess hemodynamic safety and tolerability. Systolic blood pressure will be reported in mm Hg.	Pre-dose and post-dose on Day 2 of each 3-day in-laboratory study period
Diastolic Blood Pressure Before and After Study Drug Administration	Diastolic blood pressure measured before and after administration of sublingual dexmedetomidine or placebo to assess hemodynamic safety and tolerability. Diastolic blood pressure will be reported in mm Hg.	Pre-dose and post-dose on Day 2 of each 3-day in-laboratory study period
Proportion of Required Blood Samples Collected	Proportion of protocol-specified blood samples successfully collected during the in-laboratory study periods.	Through completion of the second 3-night in-laboratory study period
Number of Participants Unable to Complete a Study Procedure Due to Intolerance	Number of participants who are unable to complete one or more protocol-specified study procedures because of intolerance, including blood draws or physiologic monitoring procedures.	From enrollment through completion of the 10-day ambulatory follow-up following the second study period
Proportion of Required Core Body Temperature Capsule Assessments Completed	Proportion of required core body temperature assessments using the ingestible telemetry capsule that are completed by participants across the pre-laboratory, in-laboratory, and post-laboratory monitoring periods.	Pre-laboratory Day 6, continuously during the 3-day in-laboratory protocol, and post-laboratory Days 4 and 6 during each study period
Proportion of Participants Adherent to Required Caffeine Restrictions	Proportion of participants who adhere to protocol-specified caffeine restrictions during required study monitoring periods.	From 72 hours before admission through completion of the 3-night in-laboratory protocol during each study period
Proportion of Participants Adherent to Required Alcohol Restrictions	Proportion of participants who adhere to protocol-specified alcohol restrictions during required study monitoring periods.	From 24 hours before admission through completion of the 3-night in-laboratory protocol during each study period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dim Light Melatonin Onset (DLMO) timing	Circadian phase assessed using dim light melatonin onset derived from serial plasma melatonin sampling during controlled dim-light conditions.	During the 3-hour dim-light period preceding habitual bedtime on each in-laboratory study day
Sleep Latency Measured by Polysomnography	Sleep latency, defined as the time from lights out to sleep onset, measured by overnight polysomnography.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Total Sleep Time Measured by Polysomnography	Total time spent asleep during the overnight sleep period, measured by polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Sleep Efficiency Measured by Polysomnography	Sleep efficiency measured by polysomnography, calculated as total sleep time divided by time in bed multiplied by 100 and reported as a percentage.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Wake After Sleep Onset Measured by Polysomnography	Total time spent awake after initial sleep onset and before final awakening, measured by polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
REM Sleep Latency Measured by Polysomnography	Time from sleep onset to the first epoch of rapid eye movement (REM) sleep, measured by polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Percentage of Total Sleep Time Spent in N2 Sleep Measured by Polysomnography	Percentage of total sleep time classified as stage N2 sleep based on polysomnography.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Percentage of Total Sleep Time Spent in N3 Sleep Measured by Polysomnography	Percentage of total sleep time classified as stage N3 sleep based on polysomnography.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Percentage of Total Sleep Time Spent in REM Sleep Measured by Polysomnography	Percentage of total sleep time classified as rapid eye movement (REM) sleep based on polysomnography.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Phase of the Core Body Temperature Circadian Rhythm	Circadian phase of the core body temperature rhythm derived from continuous core body temperature monitoring using a rectal thermistor	Continuously across the 3-day in-laboratory protocol during each study period
Amplitude of the Core Body Temperature Circadian Rhythm	Amplitude of the core body temperature rhythm derived from continuous core body temperature monitoring using a rectal thermistor.	Continuously across the 3-day in-laboratory protocol during each study period
Amplitude of the Melatonin Rhythm	Amplitude of the melatonin rhythm derived from serial plasma melatonin concentrations collected under controlled in-laboratory conditions.	Across the 3-day in-laboratory protocol during each study period
EEG Delta Oscillation Power	Delta-band EEG power derived from quantitative EEG spectral analysis during overnight polysomnography and reported in squared microvolts (µV²).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Delta Oscillation Power Density	Delta-band EEG power spectral density derived from quantitative EEG spectral analysis during overnight polysomnography and reported in squared microvolts per hertz (µV²/Hz).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Slow Oscillation Power	Slow-oscillation EEG power derived from quantitative EEG spectral analysis during overnight polysomnography and reported in squared microvolts (µV²).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Theta Oscillation Power	Theta-band EEG power derived from quantitative EEG spectral analysis during overnight polysomnography and reported in squared microvolts (µV²).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Alpha Oscillation Power	Alpha-band EEG power derived from quantitative EEG spectral analysis during overnight polysomnography and reported in squared microvolts (µV²).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Beta Oscillation Power	Beta-band EEG power derived from quantitative EEG spectral analysis during overnight polysomnography and reported in squared microvolts (µV²).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Sigma Oscillation Power During NREM Sleep	Sigma-band EEG power derived from quantitative EEG spectral analysis during non-rapid eye movement (NREM) sleep stages and reported in squared microvolts (µV²).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Slow-Wave Amplitude	Mean amplitude of detected EEG slow waves derived from quantitative EEG analysis during overnight polysomnography and reported in microvolts (µV).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Slow-Wave Slope	Mean slope of detected EEG slow waves derived from quantitative EEG analysis during overnight polysomnography and reported in microvolts per second (µV/s).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Sleep Spindle Density During NREM Sleep	Density of detected sleep spindles derived from quantitative EEG analysis during non-rapid eye movement (NREM) sleep stages and reported as the number of spindles per minute.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Sleep Spindle Frequency During NREM Sleep	Mean frequency of detected sleep spindles derived from quantitative EEG analysis during non-rapid eye movement (NREM) sleep stages and reported in hertz (Hz).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Sleep Spindle Duration During NREM Sleep	Mean duration of detected sleep spindles derived from quantitative EEG analysis during non-rapid eye movement (NREM) sleep stages and reported in seconds.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Sleep Spindle Amplitude During NREM Sleep	Mean amplitude of detected sleep spindles derived from quantitative EEG analysis during non-rapid eye movement (NREM) sleep stages and reported in microvolts (µV).	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Time Spent in N1 Sleep Measured by Polysomnography	Total time classified as stage N1 sleep based on polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Time Spent in N2 Sleep Measured by Polysomnography	Total time classified as stage N2 sleep based on polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Time Spent in N3 Sleep Measured by Polysomnography	Total time classified as stage N3 (slow-wave) sleep based on polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Time Spent in REM Sleep Measured by Polysomnography	Total time classified as rapid eye movement (REM) sleep based on polysomnography and reported in minutes.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
EEG Slow-Wave Density	Density of detected EEG slow waves derived from quantitative EEG analysis during overnight polysomnography and reported as the number of slow waves per minute.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period
Percentage of Total Sleep Time Spent in N1 Sleep Measured by Polysomnography	Percentage of total sleep time classified as stage N1 sleep based on polysomnography.	Each night (Nights 1, 2, and 3) of each 3-night in-laboratory study period

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma p-tau217 Concentrations Across the 24-Hour Sleep-Wake Cycle	Serial plasma phosphorylated tau 217 (p-tau217) concentrations measured from venous blood samples collected every 4 hours across the 24-hour sleep-wake cycle, with additional hourly sampling during the 3-hour dim-light period preceding habitual bedtime, to characterize temporal p-tau217 dynamics under sublingual dexmedetomidine and placebo conditions.	Across the 24-hour sleep-wake cycle during each in-laboratory study period
Sleep Onset Time Measured by Wrist Actigraphy	Sleep onset time derived from wrist-worn actigraphy during ambulatory monitoring.	Days 1-7 of the pre-laboratory monitoring period and Days 1-10 of the post-laboratory ambulatory monitoring period during each study period
Total Sleep Time Measured by Wrist Actigraphy	Total sleep time derived from wrist-worn actigraphy during ambulatory monitoring and reported in minutes.	Days 1-7 of the pre-laboratory monitoring period and Days 1-10 of the post-laboratory ambulatory monitoring period during each study period
Sleep Fragmentation Index Measured by Wrist Actigraphy	Sleep fragmentation index derived from wrist-worn actigraphy during ambulatory monitoring.	Days 1-7 of the pre-laboratory monitoring period and Days 1-10 of the post-laboratory ambulatory monitoring period during each study period
Sleep Efficiency Measured by Wrist Actigraphy	Sleep efficiency derived from wrist-worn actigraphy during ambulatory monitoring and reported as a percentage.	Days 1-7 of the pre-laboratory monitoring period and Days 1-10 of the post-laboratory ambulatory monitoring period during each study period
Core Body Temperature Circadian Rhythm Phase During Ambulatory Monitoring	Circadian phase of the core body temperature rhythm derived from continuous core body temperature monitoring using an ingestible telemetry capsule during pre-laboratory and post-laboratory ambulatory monitoring.	Day 6 of the 7-day pre-laboratory monitoring period and Days 4 and 6 of the 10-day post-laboratory ambulatory monitoring period during each study period
Core Body Temperature Circadian Rhythm Amplitude During Ambulatory Monitoring	Amplitude of the core body temperature circadian rhythm derived from continuous core body temperature monitoring using an ingestible telemetry capsule during pre-laboratory and post-laboratory ambulatory monitoring.	Day 6 of the 7-day pre-laboratory monitoring period and Days 4 and 6 of the 10-day post-laboratory ambulatory monitoring period during each study period
Subjective Sleep Quality Rating From Daily Sleep Diary	Subjective sleep quality assessed using a daily sleep diary on an 11-point numeric rating scale ranging from 0 (very poor) to 10 (excellent), with higher scores indicating better subjective sleep quality.	Daily during Days 1-7 of the pre-laboratory monitoring period and Days 1-10 of the post-laboratory ambulatory monitoring period during each study period
Total Sleep Time Measured by Wearable EEG	Total sleep time derived from ambulatory wearable EEG monitoring and reported in minutes.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Percentage of Total Sleep Time Spent in N3 Sleep Measured by Wearable EEG	Percentage of total sleep time classified as stage N3 sleep based on ambulatory wearable EEG monitoring.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Percentage of Total Sleep Time Spent in REM Sleep Measured by Wearable EEG	Percentage of total sleep time classified as rapid eye movement (REM) sleep based on ambulatory wearable EEG monitoring.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Time Spent in N1 Sleep Measured by Wearable EEG	Total time classified as stage N1 sleep based on ambulatory wearable EEG monitoring and reported in minutes.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Percentage of Total Sleep Time Spent in N1 Sleep Measured by Wearable EEG	Percentage of total sleep time classified as stage N1 sleep based on ambulatory wearable EEG monitoring.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Time Spent in N2 Sleep Measured by Wearable EEG	Total time classified as stage N2 sleep based on ambulatory wearable EEG monitoring and reported in minutes.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Percentage of Total Sleep Time Spent in N2 Sleep Measured by Wearable EEG	Percentage of total sleep time classified as stage N2 sleep based on ambulatory wearable EEG monitoring.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Time Spent in N3 Sleep Measured by Wearable EEG	Total time classified as stage N3 sleep based on ambulatory wearable EEG monitoring and reported in minutes.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period
Time Spent in REM Sleep Measured by Wearable EEG	Total time classified as rapid eye movement (REM) sleep based on ambulatory wearable EEG monitoring and reported in minutes.	Nights 2 and 3 of the 7-day pre-laboratory monitoring period and Nights 1, 2, and 3 of the 10-day post-laboratory ambulatory monitoring period during each study period

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Collaborators: Brigham and Women's Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): August 31, 2028
• Study Completion (Estimated): August 31, 2028

Study Registration Dates

• First Submitted: August 17, 2026
• First Submitted That Met QC Criteria: August 31, 2026
• First Posted (Actual): September 2, 2026

Study Record Updates

• Last Update Posted (Actual): September 2, 2026
• Last Update Submitted That Met QC Criteria: August 31, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: sleep; older adults; dexmedetomidine; circadian rhythm; sleep architecture; Phosphorylated Tau 217
• Other Study ID Numbers: 2026P001362

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data that underlie the results reported in publications from this study may be made available to qualified researchers upon reasonable request, subject to applicable institutional, IRB, and data-sharing requirements.
• IPD Sharing Time Frame: Beginning 6 months after publication of the primary study results and available for 5 years.
• IPD Sharing Access Criteria: Requests from qualified researchers will be considered for scientifically appropriate research purposes. Requests will be reviewed by the study investigators and/or institution, and access will be subject to applicable institutional requirements and execution of an appropriate data use agreement.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No