SLEEP 2011 Abstract Supplement

A. Basic Science V. Physiology
utes, REM minutes, REM latency) predict cortisol baseline levels after
controlling for age, BMI and gender, using linear regression analysis.
Results: REM sleep reduction (night 1 minus average of nights 2 and 3)
was associated significantly with 24-h plasma cortisol secretion. None
of the other sleep variables examined was significantly associated with
baseline cortisol levels.
Conclusion: The first night effect is stronger in individuals with increased
cortisol secretion. It appears that REM sleep reduction when sleeping in
an unfamiliar, stressful environment is a marker of increased baseline activity
of the HPA axis. This, in turn may indicate increased vulnerability
to objective sleep disturbance under stressful circumstances.
0132
FALL SLEEP PATTERNS ARE ASSOCIATED WITH WINTER/
SPRING ACUTE ILLNESS AND SCHOOL ABSENCES IN
ADOLESCENTS
Orzech KM 1,2 , Acebo C 1,2 , Barker DH 1 , Seifer R 1,2 , Carskadon MA 1,2
1
Department of Psychiatry and Human Behavior, Alpert Medical
School of Brown University, Providence, RI, USA, 2 E.P. Bradley
Hospital Sleep Research Laboratory, Providence, RI, USA
Introduction: Sleep restriction has been linked to decreased immune
function, and longitudinal data may help determine whether sleep restriction
affects the incidence and duration of acute illnesses. Our team
collected data using in-person interviews across 16 weeks to assess illness
and school absences.
Methods: Fifty-six adolescents aged 14 to 19 years (39% male) were
assigned to Long or Short sleep groups based on one week of actigraphy
during the fall (Short sleepers Mean = 5 hrs 48 [SD = 32] min;
Long sleepers Mean = 7 hrs 36 [27] min). Adolescents were interviewed
weekly in winter/spring (modal number of interviews = 13) using a
structured protocol that included 14 questions about health events.
Events were coded and entered into SPSS. For 710 completed interviews
participants reported 683 illness events and 90 school absences.
Average illness duration and rates per week were calculated for illness
bouts and school absences. Outcomes were compared between sleep and
sex groups using MANOVA.
Results: Illness bout number differed across sex and sleep groups, with
males and Long sleepers reporting fewer illness bouts (males = .26
[mean] +/- .05 [SE], females = .59 +/- .05, p < .01; Long = .33 +/- .05,
Short = .52 +/- .05, p < .01.) Illness duration, by contrast, showed no
main effect of sex or group but an interaction (p = .04) with male Long
sleepers reporting shorter illness duration than males in the Short sleep
group (male Long = .09 +/- .04, male Short = .20 +/- .03; female Long
= .21 +/- .03, female Short = .17 +/- .04). Long sleepers reported fewer
absences (Long = .07 +/- .03, Short = .18 +/- .04, p = .02.)
Conclusion: Absences and acute illnesses were more frequent in otherwise
healthy adolescents with short sleep the previous semester.
Support (If Any): Support received from the National Institute of Mental
Health (MH19927-16, MH078788-03, MH45945).
0133
TOLERANCE OF CHRONIC SLEEP RESTRICTION IN
LONG SLEEPERS DOES NOT DIFFER FOR THOSE WITH
EXISTING MORBIDITIES
Youngstedt SD 1,2 , Kline CE 1,2,3 , Zielinski M 4 , Kripke DF 5,6
1
Exercise Science, University of South Carolina, Columbia, SC,
USA, 2 Research and Development, WJB Dorn VA Medical Center,
Columbia, SC, USA, 3 Sleep Medicine Institute and Dept Psychiatry,
University of Pittsburgh Medical Center, Pittsburgh, PA, USA,
4
Program in Neuroscience, Washington State University, Spokane, WA,
USA, 5 Psychiatry, University of California, San Diego, La Jolla, CA,
USA, 6 Sleep Center, Scripps Clinic, La Jolla, CA, USA
Introduction: Over the past half-century, approximately 50 epidemiologic
studies have found a significant association of long sleep with
mortality. It has been argued that the association might represent the opposite
direction of putative causality, i.e., morbidity causing long sleep.
Contrary to this argument are findings that the association of long sleep
with mortality is just as apparent following control for morbidities, and
in samples restricted to apparently healthy individuals at initial assessment.
The argument can also be addressed by assessing responses to
sleep restriction. The aim of this investigation was to compare tolerance
to chronic moderate sleep restriction in older long sleepers with existing
morbidities vs. those who were healthier at baseline.
Methods: Forty-two adults ages 50-70 yrs who reported habitual sleep
durations of ≥ 8.5 hr were assessed. Following a two-week baseline,
participants were randomized to one of two eight-week treatments: (1)
time-in-bed (TIB) restriction of 90 min per night relative to baseline,
or (2) a control. Changes were assessed in glucose tolerance and insulin
sensitivity, sleepiness, depression, health-related quality of life,
functional outcomes of sleepiness, and a neurobehavioral performance
battery. In three sets of analyses, responses to sleep restriction were
compared between participants who were dichotomized regarding the
presence or absence of morbidity, with absence defined as (1) no morbidity,
except hypertension, high cholesterol, moderate snoring, migraine
headaches, history of hysterectomy, smoking, and allergies; (2)
no morbidity, except for hypertension and high cholesterol; (3) complete
absence of morbidity.
Results: As reported previously, TIB restriction elicited no negative effects
on any outcome. Moreover, there were no significant differences in
tolerance to TIB restriction between healthy participants and those with
existing morbidities.
Conclusion: These data provide further refutation of the argument that
morbidity causes long sleep, and the hypothesis that less healthy individuals
would be less tolerant of sleep restriction.
Support (If Any): HL71560, VA Merit, VA (VISN-7) Career Development
0134
A STUDY ON BEDROOM ENVIRONMENT AND SLEEP
QUALITY IN KOREA
Han J
Neurology, Seoul Sleep Center, Seoul, Republic of Korea
Introduction: The purpose of this study was to investigate both the
sleep environment and sleep quality in bedrooms. It was also to reveal
the relationship between sleep environment and sleep quality, and to
study its seasonal changes in winter, spring, and summer.
Methods: The subjects for this study were 24 women who lived in
apartments in Seoul and its environs. We conducted two groups of measurements.
One group considered elements of the sleep environment;
mean radiant temperature, air temperature, relative humidity, carbon dioxide
(CO2) concentration, illumination, and equivalent noise level. The
other looked at elements of sleep quality; the apneahypopnea index, and
inspiratory flow limitation (as%FL), which were measured simultaneously
while subjects were asleep.
Results: Results showed first, that people were exposed to a variety of
problems when asleep, related to their sleep environment such as too
low or high air temperatures, or relative humidity and high CO2 concentrations.
Second, these were seasonally dependant and people slept
best during spring, then winter, and then summer. Third, the effect of the
sleep environment on sleep quality varied with age.
Conclusion: The sleep environment was affected by seasonal differences,
CO2 concentration, and sleep breathing pattern.
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SLEEP, Volume 34, Abstract Supplement, 2011