NCT06694441

Noradrenergic Dysregulation, Sleep and Cognition in Older Adults With Insomnia

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: Northwestern University · Academic / Other
• Sex: All
• Age: 55 Years
• Healthy volunteers: Accepted

Summary

This study investigates the relationship between the noradrenergic (NA) system, sleep quality, and cognitive function in older adults with insomnia - a population at elevated risk for Alzheimer's disease-related dementias (ADRD) - compared to age and sex matched controls with normal sleep. The study characterizes NA function through multiple approaches: measuring 24-hour plasma levels of norepinephrine (NE) and its brain metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG); evaluating central NA system response using the clonidine suppression test (a presynaptic α2 adrenoreceptor agonist that reduces locus coeruleus NA activity; and employing pupillometry as a non-invasive marker of autonomic function. To explore NA function's mechanistic role in insomnia, the study uses an intervention with bright light exposure to enhance daytime NA activity, with the goal of improving both sleep quality and cognitive performance.

Conditions

• Insomnia

Interventions

Type	Name	Description
OTHER	Light Exposure	The intervention in this study will involve 28 (+10) days of daily exposure to bright light (BL) for two 60-minute sessions (morning and afternoon). For the intervention, we will use Re-Timer® light glasses emitting light with an intensity of 230μW/cm2 (\~500lux) with a green blue 500nm dominant wavelength (between 480-520nm). Light with these characteristics has been shown effective in suppressing melatonin levels supporting their potential to exert effects on other biological non-visual functions associated with exposure to light relevant for this study. Throughout the intervention, participants will keep a diary to monitor daily use of the glasses. Participants will have weekly phone calls with the research team to encourage compliance and monitor potential side effects.
OTHER	Placebo	Participants randomized to the control group will wear for two 60-minute sessions (morning and afternoon) customized dim-red light (RL) control Re-Timer® light glasses (wavelength peak at 632nm, light intensity \< 3 lux).

Timeline

• Start date: 2024-09-30
• Primary completion: 2029-07-31
• Completion: 2029-08-31
• First posted: 2024-11-19
• Last updated: 2026-03-30

Locations

1 site across 1 country: United States