Rest-Activity and Light
Exposure Patterns
in Older Adults:
Methodological Implications
Thomas Hornick MD
Patricia Higgins RN, PhD
1
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.
2
Biological Rhythms
Types of rhythms
1.
2.
3.
4.
Ultradian (heart beat, respirations, appetite)
Infradian (menstrual cycle)
Circannual (annual breeding cycles)
Circadian (sleep-wake cycle)
Rhythms allow organisms to time events and anticipate change!
3
Arendt 2006
4
With Zeitgeber
5
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
6
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
7
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.
8
Age related losses in retinal
illumination
Turner et al Br J Ophthalmol. 2008
November; 92(11): 1439–1444 9
.
Wikipedia, accessed 10/30/09
10
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
11
Spectral sensitivity of photopic, scotopic and
circadian (melatonin suppression) photoreception
Turner et al Br J Ophthalmol. 2008
November; 92(11): 1439–1444
12
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 melanopsincontaining ganglion cells in humans (Berson et
al, Science)
13
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
•
14
Suprachiasmatic nucleus
(SCN) is master
pacemaker
1.
2.
3.
4.
Activity in SCN correlates with circadian rhythms
Lesions of SCN abolish free-running rhythms
Isolated SCN continues to cycle
Transplanted SCN imparts rhythm of the donor on
the host
5. SCN is known to be compromised in older adults
with dementia. (Harper et al 2008)
15
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.
16
Melatonin Rhythms and Aging
Age 65-81, mean
68
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
Zeitzer et al Sleep. 2007
November 1; 30(11): 1437–1443.
17
Plasma melatonin suppression by
bright light in 65 year old man
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.
Duffy et al Neurobiol Aging.
2007 May; 28(5): 799–807.
18
Melatonin suppression with
bright light
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 4parameter logistic model fit to the
data, with the 95% confidence
interval of the model shown in the
dotted lines. For comparison, the 4parameter logistic model fit to the
data from our previous study in
younger adults [64] is shown in the
dashed line.
Duffy et al Neurobiol Aging.
2007 May; 28(5): 799–807.
19
Circadian light transfer function
Figueiro, et al. 2006
20
Clinical applications
21
Turner et al Br J Ophthalmol. 2008
November; 92(11): 1439–1444
22
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 al
JAMA 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
24
MMSE, Depression
25
Riemersma-van der Lek, R. F. et al. JAMA 2008;299:2642-2655.
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)
26
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
27
Circadian Lighting in Longterm Care: A feasibility
study
28
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)
29
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
30
31
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
32
33
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 SL3103001, S/N 9829
Light
Conditions
Photopic
(cones)
Lux
Scotopic
(rods)
Lux
S/P
Ratio
Brightness
Visual
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
34
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
35
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
36
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
37
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.

38
Methods
 Procedure
- Light exposure and restactivity 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)
39
DaysimeterTM

Research prototype
 Two light meters
measure photopic
and circadian light
exposure
 Actigraph measures
movement
40
Results
41
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
42
Ambient light exposure/24 hrs
when out of bed (lux)
Light Norms (in lux)*
Dyad data
Elder Caregiver
Range
0-449
0-3990
Mean mins:
> 20 lux
> 500 lux
>1000 lux
191.5
0.0
0.0
635.5
18.0
8.0
Sunlight
/reflective surfaces
Overcast Day
Avg nursing home
Avg living room
Twilight
Full Moon
150,000
1,000
50
50-200
10
1
*From Turner, 2008. Br J Opthalmology
43
ACTIGRAPHY
Caregiver
wife
Demented
husband
70
257
81
446
81
119
17
105
31
96
0.71
0.69
0.95
44
0.76
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)
Intra-daily variability (0-2)
Inter-daily stability (0-1)
24-hour Sleep and Light
Caregiver
Elder
45
Caregiver
46
Entrained vs Disrupted
Entrained
Human
47
Disrupted
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
48
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
49
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
50
Next Steps
“Methodology issues in a tailored
light treatment for persons with
dementia" R01 – M. Figueiro, PI
51
Wikipedia, accessed 5/2010 52
53