Individually Tailored Lighting System to Improve Sleep in Older Adults

In conjunction with investigators at the Cecil G. Sheps Center for Health Services Research, University of North Carolina (UNC) at Chapel Hill, we propose to develop and evaluate a low-cost, minimally obtrusive device that delivers individualized light therapy to adults with early-awakening insomnia - the most common sleep disturbance in older adults, and a significant problem because of its relationship to daytime sleepiness, use of potentially hazardous sleep medication, and reduced quality of life. The proposed device will measure light/dark exposure data over 24 hours, estimate optimum timing for light delivery, and deliver an individualized light dosage while subjects are asleep. Light applied through closed eyelids in the early part of the night will delay the dim light melatonin onset, a marker of the circadian clock, and help those with early sleep onset to fall asleep later

We will recruit 50 subjects who report going to bed early and desiring later bedtimes and will ask them to wear an active and an inactive light mask for 8 consecutive weeks each. A 2-week washout period between active and inactive conditions will be applied. Outcome measures will be collected periodically throughout the 8 weeks. Baseline (no intervention) will be collected prior to the active and inactive lighting interventions.

Enrolled participants will be randomized to receive either the active intervention or placebo intervention and then crossed over to receive the opposite intervention. The study consisted of two intervention periods of 8 weeks separated by a two week washout period.

The study protocol consisted of two 8-week intervention/control periods in which each participant wore either the intervention (blue light) or control (red light) mask every night, with the order of presentation of the two conditions randomized by the study's biostatistician. A light mask housing two blue Light Emitting Diodes (LED) arrays delivered a train of blue or red light pulses of 2 second duration that were presented every 30 s for no longer than 2 hr, resulting in a maximum total of approximately 240 pulses per night. the blue light mask was worn nightly for 8 weeks. There will be a two week washout period between each intervention

The study protocol consisted of two 8-week intervention/control periods in which each participant wore either the intervention (blue light) or control (red light) mask every night, with the order of presentation of the two conditions randomized by the study's biostatistician. A light mask housing two red Light Emitting Diodes (LED) arrays delivered a train of blue or red light pulses of 2 second duration that were presented every 30 s for no longer than 2 hr, resulting in a maximum total of approximately 240 pulses per night. the red light mask was worn nightly for 8 weeks, with a two week washout period between each intervention

After a two week baseline collection period, half of the subjects will initially be given light masks that deliver blue light through the closed eyelids, while subjects are sleeping. The light mask will always be turned on 120 min before estimated core body temperature minimum (CBTmin); it is expected that blue light exposure will delay the timing of the CBTmin.

After a two week baseline collection period, half of the subjects will initially be given light masks that deliver red light through the closed eyelids, while subjects are sleeping. The light mask will always be turned on 120 min before estimated core body temperature minimum (CBTmin); it is expected that red light exposure will have no effect on the timing of the CBTmin.

Pittsburgh Sleep Quality Index. Score range 0 - 21. A score over 5 is indicative of sleep disturbance. Change in score from baseline to intervention is reported. A larger difference indicates a better outcome.

The change in total amount of minutes spent sleeping at night from baseline week to the last week of intervention. A higher number is an improved outcome

The change in sleep efficiency from baseline to last week of intervention. A higher number is a better outcome. Sleep efficiency is the percentage of time spent in bed sleeping. Scored total sleep time divided by interval duration minus total invalid time (sleep/wake) of the given rest interval multiplied by 100. This data was collected using actigraphy data.

Change in sleep start time, in minutes, from baseline week to the last week of intervention. A higher number is a better outcome. Based on actigraph data

Inclusion Criteria: age 65 or older cognitively capable able to respond to study staff verbally and in English score greater than 6 using the Pittsburgh Sleepiness Quality Index suffer from insomnia suffer from excessive daytime sleepiness Exclusion Criteria: Severe sleep apnea Severe restless leg syndrome (RLS) Significant cognitive impairment History of severe photosensitivity dermatitis

Figueiro MG, Plitnick B, Rea MS. Pulsing blue light through closed eyelids: effects on acute melatonin suppression and phase shifting of dim light melatonin onset. Nat Sci Sleep. 2014 Dec 2;6:149-56. doi: 10.2147/NSS.S73856. eCollection 2014.

Figueiro MG, Bierman A, Rea MS. A train of blue light pulses delivered through closed eyelids suppresses melatonin and phase shifts the human circadian system. Nat Sci Sleep. 2013 Oct 4;5:133-41. doi: 10.2147/NSS.S52203. eCollection 2013.