Sleep Flashcards
What percentage of people work night shifts?
20%
60 million have trouble sleeping but only 10% seek help. What indirect costs does this cause?
Presenteeism - at work, no productive
increase risk of long term disability
mistakes/accidents
There has been an increase in short sleep since the 1970s. What percentages haves <6 and <7 hours?
<6 - 20&
<7 - 37%
How much sleep does the average American get?
6 hr 57 mins
What are the endogenous oscillators?
Peripheral and central
What is the central oscillator? Where is it? What does it do? How?
SCN, in hypothalamus, regulates melatonin secretion, entrainment of circadian rhythm by connecting to other tissues/organs
Where are the periperal oscillators? What do they do?
in organs, synch to the central clock - SCN
What are the RGCs? What do they do? What do they contain?
non-visual light sensitive neurones
send spectra and wavelength of light to SCN to alter melatonin secretion
also AWAKENS CORTISOL SPIKE
contains melanopsin which is most sensitive to short wavelengths (blue - 480nm)
The peripheral and central oscillators are stimulated by what 5 things?
- light INTENSITY
- Light WAVELENGTH
- ambient temperature
- Food - CARBS
- FLUID - blood osmolality
What is entrainment?
Synchronisation of oscillators based on external inputs
Sleep propensity?
ability to GET TO SLEEP and STAY ASLEEP
Cricadian rhythms?
body clock
regulated of oscillatorys
brought into rhythm to align physiology and behaviours with solar cycle
Modifiers x 3?
- Pupillary reflex - limits light getting to RGC
- Sunglasses/back lights
- SNPs - Single Nucleotide Polymorphisms
- Cutaneous fat stores - affects core/peripheral temps
- Vascular tone - affects temps/fluid volume
Two factors affecting vascular tone:
Na - vasconstriction - increases BP
NO/oestrogen - increases vasodilaton - decreases BP
What are SNPs?
Single Nucleotide Polyomorphisms
genetic variations
If SNPs are found in in gene-coding portions can lead to non-functioning/enhanced/abnormal proteins
If SNPs form in x 2 what can cause circadian rhythm to be impaired?
CRY
PER proteins
controls circadian rhythms in the peripheral oscaillators
they work by inhibiting function of other proteins until they degrade over 24 hours
What are the operators?
body’s reactions to the modifiers (pupillary reflec, sunglasses, backlights, SNPs)
- core body temp changes
- melatonin suppression/secretion
- cortisol secretion and timing of spike
- increase/decrease of blood flow
Outputs?
Sleep/function - e.g strength, stamina, food-seeking behaviour, alert, motor skills, precision, quantity and quality
Inputs?
Light Cards Exercise Fluid status Ambient temp
What effects does low daytime light exposure have?
decreased mood
decreased daytime alertness and activity
DECREASED CORE BODY TEMP
INCREASED MELATONIN SUPRESSION AT NIGHT
e.g daytime 10K lux for 6 hours can’t suppress night melatonin from 90 lux
If low light exposure 2-3 days ago, causes?
more sensitive to light at night
Blue night exposure at night causes?
increased cortisol/BP/HR
alertness
increased body temp
decreased melatonin
Blue light?
420-480nm
greatest melatonin suppression at lower intensities and shorter duration
What is the kelvin of a colour?
dominant colour at a certain temp
lower - warm colours = red, orange
higher - cooler - blue, violent
Kelvin of blue light?
650
Light intensity: moonless night moon bright industrial light overcast street light cloud day nursing home bright sunlight at noon office/kitchen households
moonless night 0.001-0.0001 moon 1 lux bright industrial light 1-5 lux overcast 2-10 lux street light 20 lux cloudy day 25 lux nursing home 50 bright sunlight at noon 100k office/kitchen 200-500 households - 50-200
What is the process of sleep onset?
darkness>pineal gland secretes melatonin> cutaneous vasodilation> warmer extremities> cools core body temp> sleep initiaion
Sleep onset to mid sleep process?
melatonin continues to rise> peripheral skin temp increases>continued core cooling> NADIR
restorative process - decreases BP and symp tone
What is NADIR?
LOW POINT core temp - reached 2-3 hours before waking
Throughout sleep?
leptin/ghrelin secretion gradual increase in cortisol FA metabolism insulin regulation ATP synthesis emotional regulation memory encoding/consolidatio DNA remodelling/repair Increase in GH increased peptide synthesis
Late sleep?
mid sleep>waking
decrease in melatonin> decrease in peripheral temp> increase in core body temp
increase in BP/symp tone/baroreceptor sensitivity as body prepares to wake
Longer REM sleep?
fear estingushing/limb system functioning
Awakening?
cortisol spike (24 hr peak)
SCN clock length most people have and ideal?
ideal - 24 hr
most - 24.2
What is a delayed phase shift?
SCN longer than 24 hrs
e.g. 1-3 hrs of evening light - delays melatonin secretion - delays sleep
What direction of travel causes a delayed phase shift to the SCN clock?
Eastward travel
can also occur with home lighting
Why are nightowls nightowls?
Mor suscepible to evening light so melatonin supressed
Advanced phase shift?
SCN clock is shorter than 24 hours
When does an advanced phase shift occur?
with light exposure early in the day
What happens to morning people?
more susceptible to desynchronisation due to morning light - so shifts them to early morning waking
If someone has a shorter cycle (<24 hrs due to being an early bird and therefore more sensitive to dysregulation) what do they need to do?
advancement of 10 minutes
If someone has a longer SCN clock (>24 hrs) and are therefore night owls, what should they do?
backwards by 20 minutes
If someone is falling asleep too late, what can alter food wise?
eat dinner earlier, eat less carbs at dinner, avoid after dinner snacks
eat high carb breakfast soon after waking
If someone falls asleep too early, what food changes can they make?
eat later carb breakfast
If you have a late breakfas or skip breakfast?
diminished cortisol awakening
breaskfast early - shifts ealier wake up time
Healthy sleep causes an increase in leptin - what does that do?
decreases food seeking behaviour
healthy sleep also decreases cortisol/glucose and improves insulin sensitivity
Impaired sleep and short duration cases?
increased NIGHT CORTISOL AND GLUCOSE decreased insulin sensitivity DECREASED DAY LEPTIN - INCREASES CARB INTAKE DECREASED TESTOSTERONE DECREASED GH INncreased CHO endoethelial dysfunction increased AGE deposition in vascular system
riased BMI, obesity, met dynrome, T2DM, CVD risk, mortality
Is someone is phased advanced they?
wake early
what exercise pattern is best for phase advancing?
morning and afternoon
if you want to phase delay - exercise?
evening exercise
WHat happens to core body temp in the afternoon?
opposite to night - core body temp increases and peripheral temp will decrease so HR and cardiac output decreases
late afternoon blood osmolality?
increases> core body temp increases to peak
(if fluid volume is decreased, less cutaneous blood flow at night, so increase cardiac activation/symp tone - shunts blood to core)
What 3 conditions are more sensitivty to melatonin suppression?
SAD
Bipolar
Major depressive disorder
What factors affect light in elderly?
cataract/corneal opacity limits light retinal exposure
naturally lower production of melatonin with age
e. g 45 yr old has 50% retinal luminance than 10 year old
e. r 65 year old, has 50% lower compared to 45year old
What is BIISS?
Behaviourally induced Insufficient sleep syndrome
voluntary sleep restriction - sleep longer on weekends
inadequate sleep for function
7-20% on pop
30-39 yrs
Alcohol abuse, working >40 hr weeks, stress, depression
Chronic Insomnia?
most common
3/week for 3 months
diff initiating and or maintaining sleep despite adequate opportunity
fatigue, impaired concentration, decrease motivation, mood, work/driving errors, headaches, GI, persisting worries about sleep
How much of OSA is undiagnosed?
Assoc?
Scale?
80%
OW/Obese/HTN/mrt syndrome/ AF
Apnoea hypopnoea Index - 5-15 mild, 15-30 mod, 30 severe
Restless leg syndrome?
5-15% US pop sens/motor uncomfortable sensation at REST LEGS can be pain/paresthesia worse - EVENINGS Jerky movements of limbs whilst awake GENETIC/ACQUIRED PHASE DELAY OF SLEEP High or low iron - no correlation with levels MG VIT D
Short sleep misperception?
less sleep then realised
secondary insomnia?
meds/vascular dysfunction/ peripheral hypoperfusion/visual impairment/renin-angiotension dysfunction
Periodic Limb Movement?
patient unware movement 30 sec intervals during sleep no abn sensations >50 years ++ assoc with restless leg syndrome may complain of restless sleep/waking in night/increase daytime sleepiness
What is the deepest stage of sleep?
Non-REM sleep, stage 3 - slow-wave
healthy sleep will have high proportion
increases learning/memory/fast cognitive processing/ fear extinguishing
Impaired sleep causes decreased?
BDNF - misinterpretation of social cues, decrease alertness/cog processing/diminished fear extinguishment (amygdala unable to get rid of fearful events), impaired learning
CV changes with good duration and quality of sleep?
decreased symp tone
increase high periperhal perfusion and core body temp decrease
INCREASE CV STAMINA AND CV RECOVERY TIME
Impaired sleep - CV effects?
increase symp tome, endoethelial injury, increase Cho, HTN esp at night, decreased peripheral perfusion
NO REDUCTION IN BP IN EARLY HOURS
increased risk of MI/CVD DEATH/VASOSPASTIC DISORDERS
Poor sleep is associated with which cancers?
BEPCA
breast endometrial prostate colorectal AML
Cancer and poor sleep risk factors?
poor sleep - increases cancer stimulating cytokines - IL10
aberrant DNA methylation
Healthy sleep helps - DNA repair/histone remodelling, apoptosis and anti-cancer cytokines - IL1, IL2, TNFalpha
Short sleep deprivation:
pms
PTSD and traumatic brain injury worse if poor sleep before or after
Lifestyle changes for better sleep?
naps <30 mins Bed - S&S only regular sleep/wake times natural cooling throughout night peripheral warming- hot de caff drinks/socks/heat pads/bath and showers hide alarm clocks/light
How to improve with respect to light?
increase daytime light exposure outdoors
decrease light at night - turn off lights/dim lights 1 hr before bed especially blue light
What spectrum of light to use at night?
2500k colour warm
Diet changes for better sleep?
limit day caffeine/no night caffeine no ALCOHOL 3 HOURS BEFORE BED NO AFTER DINNER SNACKS ADEQUATE DAYTIME FLUID (esp late afternoon) avoid Na esp at dinner optimise weight
PA to improve sleep?
increase morning or late afternoon PA
AT LEAST ONE HOUR A DAY
Stress for better sleep?
settle down 1 hr before bed - music 60 bpm/editation
windown routine
stop stimulating things 90 mins before bed
MBSR/CBT
Intensive treatments for chronic insomnia?
1st line - chronic insomnia - more likely sustained benefit
behavioural/stimulus control/rlaxation therapy/sleep hygiene
good for >60 yrs
Significant differences in endogenous?
melatonin between individuals
Supplemental melatonin:
best bioavailability?
sustained preps best for?
no adverse effects at dose?
sublingual
westward jet lag - but may cause morning jet lag
1-6mg - but may interaction with some cytochrome P-450 drugs
Hypnotic meds risks?
death - esp 18-55years
increased all cause mortality in all age groups - OD, car accidents, falls, deperssion, cancer, suicide
Difficulty maintaining sleep - tx?
dark room, cool glass of water near bed, cooling room increase morning and mid afternoon light avoid turning lights on if wakes increase later afternoon hydration avoid evening soda/alc/caff exercise without creating pain stress mx
Sleep deficiency from early waking - tx?
warm bedcovers
avoid light until wake up time
increase PA
increase late afternoon sunlight to stimulate melatonin
Jet leg travelling east?
hearty breakfast within 30-45 mins of new wake up time
GET LIGHT ESP OUTDOORS CLOSE TO NEW WAKE UP TIME
DIM LIGHT 1 HOUR PRIOR TO NEW SLEEP TIME
melatonin 1mg SL 1 hour before new bedtime
Jet lag travelling west?
GET LATE AFTERNOON AND EVENING LIGHT
AVOI DIM LIGHT UNTIL 1 HOUR BEFORE NEW BEDTIME
BREAKFAST 30-45 MINS AFTER WAKE UP TIME
COMPLEX CARBS 2-3 HRS BEFORE NEW SLEEP TIME
1 MG SL melatonin
Does P.I ncrease of decrease tiredness?
2-4 times more likely to be tired
restless legs more common in?
DM
Dyssommnia? Parasomnia?
sleep disordes that negatively impact quantity and quality of sleep
unusual physical events before sleep/during sleep/arousal e.g. abn movements/sleep terrors
> 8.5hrs assoc with?
obesity
Sustained release melatonin
best for westward travel but morn drowsiness
how long should sleep diaries be?
one week (for first visit)
STOP is an assessment tool for?
OSA
snore loudly? tired? observed you stop breathing? pressure? BP Bmi>35, large nexk 40cm, M
> 2 increased risk
sleep cycle?
- theta - very light - hallucinations
- light/transitional - theta + K-complex
- deep sleep - theta and delta
- deep - only delta
- REM - dream sleep
coffee blocks?
adenosine R
red light
2500k
short term sleep deprivation can increase?
BP
cortisol increases?
morning, up by 50% in 20-30 mins from waking
sleep depreivation ghrelin and leptin
ghrelin - increases appetite and obesity
leptop decreases appetite
irregular sleep affect on leptin
decreases appetite
Sleep for: newborns 0-3m infants - 4-11months toddler 1-2 years pre-school 3-5yrs school age 6-13 yrs teens 14-17 yrs younger adult - 18-25yrs adults 26-64yrs older adult >65
newborns 0-3m - 14-17 hrs infants - 4-11months - 12-15 hrs toddler 1-2 years - 11-14 hrs pre-school 3-5yrs 10-13 hrs school age 6-13 yrs 9-11 hrs teens 14-17 yrs 8-10 hrs younger adult - 18-25yrs 7-9 hrs adults 26-64yrs 7-9 hrs older adult >65 7-8 hrs
REM sleep at different ages?
50% in REM sleep
25% 10 yrs old
15% over 50 yrs
