Rest-Activity and Light Exposure Patterns

in Older Adults: Methodological Implications

Thomas Hornick MD

Patricia Higgins RN, PhD

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Objectives

Understand the influence of circadian rhythm disruptions on overall health.

Identify clinical characteristics of circadian rhythm disturbances in older adults

Recognize the importance of chronobiology in elders’ sleep-wake disturbances.

Describe results from preliminary studies assessing the use of circadian light therapy in a nursing home unit and measurement of circadian light exposure in a case study of home-dwelling older adults. 

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Types of rhythms

1. Ultradian (heart beat, respirations, appetite)

2. Infradian (menstrual cycle)

3. Circannual (annual breeding cycles)

4. Circadian (sleep-wake cycle)

Rhythms allow organisms to time events and anticipate change!

Biological Rhythms

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Arendt 2006 4

With Zeitgeber

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Disruption of circadian rhythm

• Poor performance/fatigue (Reinberg et al, 2007, Laposky et al 2008)

• Weight gain(Knutson et al, 2007)• Breast cancer (Stevens et al 2001)• Other conditions

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Why older adults?

• Sleep disorders are common• Complaints among caregivers of persons

with dementia frequently revolve around disordered day/night cycles

• Medications for sleep are less safe in this population

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Aging and light

• Older adults spend much of their time in muted indoor lighting.

• 35 minutes/day of bright light exposure compared to approximately 58 minutes of bright light per day for middle-aged adults. (Sanchez 1993)

• Reduced light exposure compounded due to physiologic changes

• senile meiosis, cataract formation, and/or increased light absorption by the crystalline lens. (Charmin 2003)

• Attenuation of light exposure by more than 80% in normal older adults relative to young adults.

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Age related losses in retinal illumination

Turner et al Br J Ophthalmol. 2008 November; 92(11): 1439–1444 9

.

Wikipedia, accessed 10/30/09

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Role of Retinal Receptors

Three known retinal receptors: process visual and circadian timing information

Rods and cones: visual data Intrinsically photosensitive retinal ganglion

cells (iPRGC): primarily light-dark data

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Turner et al Br J Ophthalmol. 2008 November; 92(11): 1439–1444

Spectral sensitivity of photopic, scotopic and circadian (melatonin suppression) photoreception

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iPRGCs: History

1998: Melanopsin in light-sensitive cells on frog skin (Provencio et al, Proc Natl Acad Sci )

2000: Melanopsin-containing cells found in retinal ganglion cell layer (Provencio et al, J Neuroscience)

Most likely comprise the retinohypothalamic tract Sensitive to wavelengths in the 484-500 nm (blue

light) 2002: Light responses from melanopsin-

containing ganglion cells in humans (Berson et al, Science)

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Intrinsically photosensitive retinal ganglion cells (iPRGCs)

Timing Photoreceptors• Located throughout retina (~3000)• Express melanopsin

• Blue light sensitive(peak 460nm)• Regulate photoperiodism (sensitivity to length

of day and night)• Higher excitatory threshold than rods/cones• Transmits to SCN

24-hour light-dark pattern on the retina is the most efficient stimulus for entrainment of circadian rhythms in humans

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Suprachiasmatic nucleus (SCN) is master

pacemaker

1. Activity in SCN correlates with circadian rhythms2. Lesions of SCN abolish free-running rhythms3. Isolated SCN continues to cycle4. Transplanted SCN imparts rhythm of the donor on

the host5. SCN is known to be compromised in older adults with

dementia. (Harper et al 2008)

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Role of Melatonin

Melatonin• Primary role in humans is to convey

information about the daily light-dark cycle to physiological systems

• Peaks during sleep, suppressed by light.

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Melatonin Rhythms and Aging

Zeitzer et al Sleep. 2007 November 1; 30(11): 1437–1443.

Average (±SEM) plasma melatonin in young (top, n=90) and older (bottom, n=29) subjects during a normally phased sleep episode (closed boxes) and a constant routine where they remained awake at the same clock hours (open circles). Data were aligned such that each subject's wake time was graphically adjusted to 08:00 and the data from the baseline day and night and from the CR(constant routine) expressed relative to wake time; sleep time is from 24:00 to 08:00. Melatonin data were averaged hourly within and then across subjects

Age 65-81, mean 68

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Plasma melatonin suppression by bright light in 65 year old man

Duffy et al Neurobiol Aging. 2007 May; 28(5): 799–807.

Plasma melatonin data from subject 19G7, a 65 year old man who was exposed to a 3,527 lux light stimulus. Upper panel: plasma melatonin data from the initial circadian phase estimation procedure (CR1); middle panel: plasma melatonin data from the intervention day, with the 6.5-h experimental light exposure indicated by the open box; lower panel: plasma melatonin data from the final circadian phase estimation procedure (CR2) shown in the solid symbols, with data from CR1 replotted from above in the open symbols. During CR1, the fitted peak of the melatonin secretion (MELmax) occurred at 03:45, 3.5 h before habitual wake time. During CR2 MELmax occurred at 06:30, a 3.5 h phase delay. Melatonin was suppressed by 78% during the 6.5-h 3,527 lux light stimulus.

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Melatonin suppression with bright light

Duffy et al Neurobiol Aging. 2007 May; 28(5): 799–807.

Phase shift of fitted plasma melatonin peak (MELmax) vs. illuminance of experimental light stimulus. Data from each of the ten subjects are plotted individually and shown with square symbols. Solid line represents the 4-parameter logistic model fit to the data, with the 95% confidence interval of the model shown in the dotted lines. For comparison, the 4-parameter logistic model fit to the data from our previous study in younger adults [64] is shown in the dashed line.

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Circadian light transfer function

Figueiro, et al. 2006

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Clinical applications

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Turner et al Br J Ophthalmol. 2008 November; 92(11): 1439–1444

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Therapeutic light 2 Hours bright light in AM

Improved sleep efficiency in NH residents Fetveit et al, 2003

30 minutes sunlight for five days Decreased napping Increased participation Alessi et al, 2005

Daytime bright light Improved sleep/wake cycle in persons with

dementia (van Someren et al,1997)23

Riemersma-van de Lek et alJAMA 2008

6/12 Homes randomized for lighting intervention Installed fluorescent fixtures, both real and

sham 1000 lux horizontal at eyes in intervention Caregivers unaware which arm randomized to

Melatonin randomized by patient 3.5 year follow up

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Riemersma-van der Lek, R. F. et al. JAMA 2008;299:2642-2655.

MMSE, Depression

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Schedule change: Shift work

Light at night (LAN) Nurses’ Health Study (Willet, PI) Effects of Light at Night on Circadian System in

Nurses (Schernhammer, PI, RO1-OH008171)

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Circadian phase shifters

Can have negative effects on health Abrupt: jet lag, shift work Gradual: institutionalization

Timed light exposure: reset clock Sensitivity age-related Bright light in morning advances the clock Bright light in evening delays the clock Delays easier than advances

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Circadian Lighting in Long-term Care: A feasibility

study

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Methods 3 participants, residents of Ward 62B Lighting: GE fluorescent ceiling lamps

14,000 K Instruments

Sleepwatch-L© (AMI, Ardsley, NY) Neuropsychiatric Inventory-Nursing Home

Version DaysimeterTM (Lighting Research Center,

Rensselear Polytechnic Institute)

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Methods/Instrumentation for Sleep/Light Data

Subject wore Sleep Watch-L© for 7 days

Wrist-worn electronic measure of body movement and light

Software calculates activity/inactivity and light

© Ambulatory Monitoring Inc

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Lighting Installation

VAMC safety standards 1st phase: 3 ‘blue lamp’ prototypes by GE:

8000 Kelvin (K); 14,000K;16,000K 2nd: 13 standard fluorescent lighting ceiling

light fixtures in Dayroom 7 of 13 changed to 14,000 K (6 remained @

5000 K) Timer controlled blue lighting on, 8a-6p Lighting after 6pm: sufficient for visual acuity

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Mean of light measurements taken at eye level (horizontally) at 8 points in the room in the 4 cardinal directions, using PMA 2200 Photoradiometer, SnP Meter Photopic SL3103-001, S/N 9829

Light Conditions

Photopic (cones)

Lux

Scotopic (rods)

LuxS/P

Ratio BrightnessVisual

Effectiveness

all on 517 1178 2.24 781 1818

14,000 K only 381 918 2.26 606 759

standard 333 725 2.14 491 609

all off 222 489 2.17 328 412

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Results & Conclusions

Wrist actigraph well accepted Light sensor on wrist covered much of the

time by clothing? New blue lighting well received 3 subjects exposure to blue lighting (time

in Dayroom/ 10 hr period): 77 minutes, 371 mins, 373 mins

Next time: Change installation pattern?, use DaysimeterTM

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Rest-Activity and Light Exposure Patterns in the Home

Setting: A Methodological Study

P. Higgins, T. Hornick, M. Figueiro

American J Alzheimer’s Disease and Other Dementias, 2010

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Purpose

Assess the feasibility and reliability of using a circadian light meter (DaysimeterTM) in a field setting and use the human circadian phototransduction model’s analyses to provide clinically relevant results

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Dyad

Caregiver – Wife, 73 years, “good health”, no vision problems, no sleep-aid meds. Primary caregiver

Elder – Husband, 80 years, vascular dementia plus multiple co-morbidities, continent, needed assistance for all ADL’s and IADL’s, multiple meds included antidepressant but no sleep-aid

Elder received all primary care from the Cleveland VA Geriatrics Clinical team.

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Methods

Procedure - Light exposure and rest-activity data were collected over 7 consecutive days in November, 2007

Instruments Assessment of sleep quality and habits Home visit Sleepwatch-L© (AMI, Ardsley, NY) DaysimeterTM (Lighting Research Center,

Rensselear Polytechnic Institute)

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DaysimeterTM

Research prototype Two light meters measure photopic and

circadian light exposure Actigraph measures movement

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Results

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Built Environment

Independent living complex for seniors Apartment: 640 square feet

Brown paneling and beige paint and carpet One south facing window in bedroom Sliding glass door onto porch (south facing) Standard florescent lighting: kitchen and bath Incandescent lighting: floor and table lamps

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Ambient light exposure/24 hrs when out of bed (lux)

Light Norms (in lux)*

Sunlight/reflective surfaces 150,000Overcast Day 1,000Avg nursing home 50Avg living room 50-200Twilight 10Full Moon 1

*From Turner, 2008. Br J Opthalmology

Range

Mean mins: > 20 lux > 500 lux >1000 lux

Elder

0-449

191.5 0.0

0.0

Caregiver

0-3990

635.5 18.0 8.0

Dyad data

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ACTIGRAPHY Caregiver

wifeDemented

husband

Sleep-rest

- Mean sleep efficiency % - Mean night sleep (mins) - Mean sleep latency

(mins) - Mean wake after sleep

onset [WASO] (mins) - Mean napping/24 hr

(mins)

70 257

81 119

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81446

17105

96

Intra-daily variability (0-2) 0.71 0.95

Inter-daily stability (0-1) 0.69 0.7644

Caregiver

Elder

24-hour Sleep and Light

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Caregiver

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Entrained vs Disrupted Entrained Disrupted

Human

Conclusions

Daily light levels are very low Little variation in light levels Sleep

Neither caregiver or elder sleep well Caregiver: poor circadian entrainment

Sleep disruption causes Low lighting, little contrast Frequent wake times at night

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Support

VISN 10 GRECC, Cleveland VAMC Frances Payne Bolton School of Nursing,

Case Western Reserve University, Cleveland, OH

Lighting Research Center, Rensselear Polytechnic Institute, Troy NY

General Electric Company, Nela Park, East Cleveland, OH

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Team

Tom Hornick, MD1,2

Patricia Higgins, PhD1,2 Mariana Figueiro, PhD3

Mark Rea, PhD3

Andy Bierman, MS3

John Bullough, PhD3

Bill Biers, PhD4 Mark Duffy, PhD4

Ed Yandek, BS4

1Case Western Reserve University

2Cleveland Veterans Affairs Medical Center

3Lighting Research Center, Rensselaer Polytechnic Institute

4General Electric Lighting, Nela Park

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Next Steps

“Methodology issues in a tailored light treatment for persons with

dementia" R01 – M. Figueiro, PI

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Wikipedia, accessed 5/2010 52

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