Download - L'importanza del sonno

MMSleep &

Chronophysiology Laboratory

The Importance of Sleep and Sleep Hygiene: Practical Clues for the

College Student

Roseanne Armitage, Ph.D.

Professor

Director - Sleep and Chronophysiology Laboratory

University of Michigan

Functions of SleepSWS – basic sleep drive – rest, recovery &

homeostasis

Body& blood cell work, immune system,

Keep circadian rhythms entrained

Stage 2 – maintain vigilance while sleeping

REM- Memory consolidation,

development of neural connections

in childhoodMM

Sleep & Chronophysiology

Laboratory

AMPS

POWERSPECTRA

% ZERO-CROSS% FIRST DERIVATIVE

POWER

*FREQUENCY BAND WIDTHS DIFFER BETWEEN LABORATORIES

A/D CONVERSIONBOARD RESIDENT

IN COMPUTERSAMPLING RATE

128-1000Hz

BETA 12-32 Hz*SIGMA 12-16 HzALPHA 8-12 HzTHETA 4-8 HzDELTA 0.5-4 Hz

PSA or PAA

RAW DATA STORAGE

DIGITIZED VALUES

OFF-LINE VISUAL SLEEP-STAGESCORING

Stage 4

AwakeMoveREMStg 1Stg 2Stg 3Stg 4

SLEEP EFFICIENCY: 96.8%REM LATENCY: 94.5 minSLEEP LATENCY: 7.0 min

% REM: 13.3% STAGE 1: 7.5% STAGE 2: 57.0% STAGE 3: 16.9% STAGE 4: 3.5

SOS: 23:54:00 TIME OF NIGHT WUT: 08:51:30

HEALTHY NORMAL CONTROL

How much sleep do you need?

• Not everyone needs the same amount of sleep Natural short and long sleepers

• BUT sleeping less than 6.5 or more than 9 hours is associated with 1.7 x greater mortality & risk of disease.

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Is it Enough Sleep? More than 40 % of adults have sleep

complaints 25 % women & 16 % men

# 1 Complaint: Feeling unrested # 2 Complaint: Difficulty Falling Asleep

Among college students 71 % had sleep complaints in 2000 compared to 24 % in 1978

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How Has Sleep Changed Historically?

Estimated 8-9 hrs in early 20th Century 7-8 hrs mid 1980s-2002 College Students:

1980s reported 7-7.5 hrs 2002 reported 6-6.9 hrs

Going to bed later is the culprit Bedtime is 1-2 hrs later

than it was 25 yrs ago

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Napping

30-50 % of students nap Nappers have delayed bedtime of >1 hr 30 % naps >1.7 hrs Mostly late afternoon naps Sleep >1 hr less than non nappers

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Consequences of Sleep Loss

Poor academic performance correlated with insomnia & poor sleep quality

Automobile Accidents: Fatigue is a leading cause Minor medical Illness: Cold & Flu rates higher in

poor sleepers Circadian dysregulation: Creating Jet Lag in the

home environment

Psychiatric Illness: Depression & Anxiety

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Sleep & Depression

Sleep disturbance > 2 wks is a risk factor for the development of depression

Sleep abnormalities are common symptoms of depression: >80% pts

Often the presenting symptom: Common to notice the sleep problem first

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Sleep & Depression

Worse clinical outcome and increased risk of relapse in recovering patient

Increased risk of suicide Daytime fatigue/ reduced functioning Worry about insomnia may cause

further insomnia and anxiety

If sleep problems persist into clinical remission:

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Depression in College Students

Incidence is 2 x greater than general population Approximately 20 % of students

Often goes undiagnosed and untreated Increasing risk of another episode

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Sleep and Depression in College Students

Worsening of depression and sleep problems at exam time (particularly in males)

Minor medical problems 2-4 x more prevalent in depressed students with sleep problems >2 wks duration

Attending University does increase

both incidence of sleep problems

& depression

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AwakeMoveREMStg 1Stg 2Stg 3Stg 4

SLEEP EFFICIENCY: 79.2%REM LATENCY: 49.0 minSLEEP LATENCY: 6.0 min

% REM: 16.9% STAGE 1: 17.0% STAGE 2: 46.0% STAGE 3: 0.0% STAGE 4: 0.0

SOS: 01:04:00 TIME OF NIGHT WUT: 08:51:30

DEPRESSED PATIENT

Sleep & Biological Rhythms

Ultradian <24 hrs Most common 90 min REM/NREM sleep cycle Task Performance

Infradian >24 hrs Lunar cycle Menstrual cycle

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Circadian Rhythms 24 hr rhythms in biology, physiology, mood &

performance that are entrained to the light dark cycle

Controlled by the SCN in the hypothalamus Light is the most potent zeitgeber

Sleep, Cardiovascular Activity, Body Temperature, Hormones, Endocrine & Metabolic Function,

Liver & Kidney Function, Gastrointestinal Activity, Immunology

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HIGH COHERENCE

LOW COHERENCE

100

100

0

0

EPOCHS

EPOCHS

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200

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% T

ime-

In-F

req

uen

cy%

Tim

e-In

-Fre

qu

ency

C3

C4

.99

.43

Coherence in Girls at High-RiskCoherence in Girls at High-Risk

0.2

0.4

0.6

0.8

1

HIGH RISK NC

CUTPOINT= .70

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>50 % of girls with extreme low >50 % of girls with extreme low values had 1st episode 3-5 yrs latervalues had 1st episode 3-5 yrs later

How Do We Improve Sleep & Depression In College Students?

Education about Sleep Education about Depression Clearly identify Biological & Familial Risks Early Intervention Development of Easy,

Practical Guidelines for

Good Sleep HygieneMM


Laboratory

Good Sleep & Biological Rhythm Hygiene

Maintain regular rise & bed times every night including weekends i.e. 11:00 P.M.-6:00 A.M. ESPECIALLY FOR WOMEN

Very hot bath (~15 min. Duration) 1 1/2 hour before bedtime ESPECIALLY FOR SWS PROBLEMS

Turn down thermostat, no electric blankets Use very dark curtains or use a sleep mask

No napping especially in afternoon

or eveningMM


Laboratory

Restrict caffeine (not just coffee) 1-2 cups before 10

a.m.

Warm milk 1/2 hour before bedtime

No food or exercise within 2 hrs of bedtime

Avoid time zone changes

Good Sleep & Biological Rhythm Hygiene

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Schedule for Light Exposure

• Early morning bright light will advance the circadian clock i.e make you sleepy earlier

• Late afternoon bright light will delay your body clock i.e make you sleepy later

• Wear dark glasses to minimize light to retina if your body clock is already shifted

• Avoid bright light at night, use incandescent light with the lowest wattage possible.

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